Trial Outcomes & Findings for Study to Evaluate Imetelstat (GRN163L) in Participants With International Prognostic Scoring System (IPSS) Low or Intermediate-1 Risk Myelodysplastic Syndrome (MDS) (NCT NCT02598661)

Last Updated: 2026-01-05

Results Overview

Percentage of participants without any RBC transfusion during any consecutive 8 weeks (56 days) starting from Study Day 1 until subsequent anti-cancer therapy if any were reported. Study Day 1 is defined as the day of the first dose for participants enrolled in Phase 2. The 95% confidence interval (CI) was calculated using Clopper-Pearson method. Percentages were rounded off to the nearest single decimal place.

Recruitment status

ACTIVE_NOT_RECRUITING

Study phase

PHASE2/PHASE3

Target enrollment

289 participants

Primary outcome timeframe

Up to 5 years in Phase 2

Results posted on

2026-01-05

Participant Flow

Participants were enrolled in Phase 2 at 48 study sites and in the Phase 3 Study at 77 study sites. Data is reported for the Phase 2, Phase 3 and QTc substudy up to the primary completion date (PCD) of 13 October 2023. Enrolment in Extension phase started after October 2023 and analyses for the participants in extension phase is still ongoing, hence data for extension phase will be reported at study completion date in 2026.

57 participants with MDS received Imetelstat Sodium in Phase 2, followed by Phase 3 where 178 participants were randomized to receive either Imetelstat Sodium or Imetelstat sodium-matching placebo. 54 participants enrolled in QTc Substudy to receive either Imetelstat Sodium or Imetelstat sodium-matching placebo.

Participant milestones

Participant milestones
Measure	Phase 2: Imetelstat Sodium Imetelstat sodium administered intravenously (IV), at a starting dose of 7.5 milligrams per kilogram (mg/kg), every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Imetelstat Sodium Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	QTc Substudy: Imetelstat Sodium Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	QTc Substudy: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. If after a minimum of 2 treatment cycles a participant has no significant change to pRBC transfusion burden or evidence of clinical benefit per Investigator, after discussion with the Sponsor the participant, he/she may be permitted to start treatment with imetelstat sodium.
Overall Study STARTED	57	118	60	35	19
Overall Study Crossover to Imetelstat	0	0	0	0	14
Overall Study Target Population	38	0	0	0	0
Overall Study COMPLETED	15	57	29	33	17
Overall Study NOT COMPLETED	42	61	31	2	2

Reasons for withdrawal

Reasons for withdrawal
Measure	Phase 2: Imetelstat Sodium Imetelstat sodium administered intravenously (IV), at a starting dose of 7.5 milligrams per kilogram (mg/kg), every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Imetelstat Sodium Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	QTc Substudy: Imetelstat Sodium Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	QTc Substudy: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. If after a minimum of 2 treatment cycles a participant has no significant change to pRBC transfusion burden or evidence of clinical benefit per Investigator, after discussion with the Sponsor the participant, he/she may be permitted to start treatment with imetelstat sodium.
Overall Study Death	27	34	14	1	0
Overall Study Lost to Follow-up	2	3	2	0	0
Overall Study Withdrawal by Subject	13	24	14	1	1
Overall Study Adverse Event	0	0	1	0	0
Overall Study Randomized, Never Treated	0	0	0	0	1

Baseline Characteristics

Study to Evaluate Imetelstat (GRN163L) in Participants With International Prognostic Scoring System (IPSS) Low or Intermediate-1 Risk Myelodysplastic Syndrome (MDS)

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Phase 2: Imetelstat Sodium n=57 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Imetelstat Sodium n=118 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo n=60 Participants Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	QTc Substudy: Imetelstat Sodium n=35 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	QTc Substudy: Placebo n=18 Participants Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. If after a minimum of 2 treatment cycles a participant has no significant change to pRBC transfusion burden or evidence of clinical benefit per Investigator, after discussion with the Sponsor the participant, he/she may be permitted to start treatment with imetelstat sodium.	Total n=288 Participants Total of all reporting groups
Age, Continuous	70.1 years n=9667 Participants	70.4 years n=6597 Participants	71.7 years n=16264 Participants	69.7 years n=31 Participants	67.8 years n=21 Participants	69.9 years n=3 Participants
Sex: Female, Male Female	25 Participants n=9667 Participants	47 Participants n=6597 Participants	20 Participants n=16264 Participants	8 Participants n=31 Participants	2 Participants n=21 Participants	102 Participants n=3 Participants
Sex: Female, Male Male	32 Participants n=9667 Participants	71 Participants n=6597 Participants	40 Participants n=16264 Participants	27 Participants n=31 Participants	16 Participants n=21 Participants	186 Participants n=3 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	1 Participants n=9667 Participants	6 Participants n=6597 Participants	5 Participants n=16264 Participants	0 Participants n=31 Participants	0 Participants n=21 Participants	12 Participants n=3 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	48 Participants n=9667 Participants	100 Participants n=6597 Participants	48 Participants n=16264 Participants	29 Participants n=31 Participants	15 Participants n=21 Participants	240 Participants n=3 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	8 Participants n=9667 Participants	12 Participants n=6597 Participants	7 Participants n=16264 Participants	6 Participants n=31 Participants	3 Participants n=21 Participants	36 Participants n=3 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=9667 Participants	0 Participants n=6597 Participants	0 Participants n=16264 Participants	0 Participants n=31 Participants	0 Participants n=21 Participants	0 Participants n=3 Participants
Race (NIH/OMB) Asian	2 Participants n=9667 Participants	8 Participants n=6597 Participants	2 Participants n=16264 Participants	3 Participants n=31 Participants	0 Participants n=21 Participants	15 Participants n=3 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=9667 Participants	0 Participants n=6597 Participants	0 Participants n=16264 Participants	0 Participants n=31 Participants	0 Participants n=21 Participants	0 Participants n=3 Participants
Race (NIH/OMB) Black or African American	1 Participants n=9667 Participants	1 Participants n=6597 Participants	2 Participants n=16264 Participants	1 Participants n=31 Participants	1 Participants n=21 Participants	6 Participants n=3 Participants
Race (NIH/OMB) White	46 Participants n=9667 Participants	95 Participants n=6597 Participants	48 Participants n=16264 Participants	29 Participants n=31 Participants	15 Participants n=21 Participants	233 Participants n=3 Participants
Race (NIH/OMB) More than one race	0 Participants n=9667 Participants	0 Participants n=6597 Participants	0 Participants n=16264 Participants	0 Participants n=31 Participants	0 Participants n=21 Participants	0 Participants n=3 Participants
Race (NIH/OMB) Unknown or Not Reported	8 Participants n=9667 Participants	14 Participants n=6597 Participants	8 Participants n=16264 Participants	2 Participants n=31 Participants	2 Participants n=21 Participants	34 Participants n=3 Participants

PRIMARY outcome

Timeframe: Up to 5 years in Phase 2

Population: Phase 2: All Treated Analysis Set included all participants who received at least one dose of study drug.

Outcome measures

Outcome measures
Measure	Phase 2: Imetelstat Sodium n=57 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Imetelstat Sodium Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.
Phase 2: Percentage of Participants Without Any Red Blood Cell (RBC) Transfusion During Any Consecutive 8-Weeks Period (All Participants)	36.8 percentage of participants Interval 24.45 to 50.66	—	—	—

PRIMARY outcome

Timeframe: Up to 5 years in Phase 2

Population: Phase 2: Target Population included participants without prior hypomethylating agent (HMA) or lenalidomide use and non del(5q) in karyotype at baseline.

Outcome measures

Outcome measures
Measure	Phase 2: Imetelstat Sodium n=38 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Imetelstat Sodium Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.
Phase 2: Percentage of Participants Without Any RBC Transfusion During Any Consecutive 8-Weeks Period in Target Population	42.1 percentage of participants Interval 26.31 to 59.18	—	—	—

PRIMARY outcome

Timeframe: Up to 3.7 years in Phase 3

Population: Phase 3: The ITT Analysis Set included all participants randomized into the Phase 3 study.

Percentage of participants without any RBC transfusion during any consecutive 8 weeks (56 days) starting from Study Day 1 until subsequent anti-cancer therapy if any were reported. Study Day 1 is defined as the day of the first dose for participants enrolled in Phase 2. The 95% CI was calculated using Clopper-Pearson method. Percentages were rounded off to the nearest single decimal place.

Outcome measures

Outcome measures
Measure	Phase 2: Imetelstat Sodium n=118 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Placebo n=60 Participants Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Imetelstat Sodium Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.
Phase 3: Percentage of Participants Without Any RBC Transfusion During Any Consecutive 8-Weeks Period	39.8 percentage of participants Interval 30.93 to 49.25	15.0 percentage of participants Interval 7.1 to 26.57	—	—

SECONDARY outcome

Timeframe: Adverse events: Up to 5 years in Phase 2 and up to 3.7 years in Phase 3; Deaths: Up to 6.6 years in Phase 2 and up to 4 years in Phase 3

Population: Phase 2 and Phase 3: Safety Analysis Set included all participants who received at least one dose of study drug.

TEAEs were defined as those events that 1) occurred after the first dose of study drug, through the treatment phase, and for 30 days following the last dose of study drug or until subsequent anti-cancer therapy if earlier; 2) any event that was considered study drug-related regardless of the start date of the event; or 3) any event that was presented at baseline but worsened in severity or was subsequently considered drug-related by the investigator. Serious TEAEs are any TEAEs that result in death, is life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, is a congenital anomaly/birth defect, is a suspected transmission of any infectious agent via a medicinal product, is medically important. Any clinically significant vital sign measurements, clinical laboratory values, and electrocardiogram (ECG) findings were reported as TEAEs. TEAEs included both serious and non-serious TEAEs.

Outcome measures

Outcome measures
Measure	Phase 2: Imetelstat Sodium n=50 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Placebo n=7 Participants Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Imetelstat Sodium n=118 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo n=59 Participants Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.
Phase 2 and Phase 3: Number of Participants With Treatment Emergent Adverse Events (TEAEs) and Deaths Participants with AEs	50 Participants	6 Participants	117 Participants	59 Participants
Phase 2 and Phase 3: Number of Participants With Treatment Emergent Adverse Events (TEAEs) and Deaths Participants who died	24 Participants	3 Participants	35 Participants	15 Participants

SECONDARY outcome

Timeframe: Up to 5 years in Phase 2 and up to 3.7 years in Phase 3

Percentage of participants without any RBC transfusion during any consecutive 24 weeks (168 days) starting from Study Day 1 until subsequent anti-cancer therapy if any were reported. Study Day 1 is defined as the day of the first dose for participants enrolled in Phase 2 and the day of randomization for participants enrolled in Phase 3. The 95% CI was calculated using Clopper-Pearson method. Percentages were rounded off to the nearest single decimal place.

Outcome measures

Outcome measures
Measure	Phase 2: Imetelstat Sodium n=57 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Placebo n=118 Participants Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Imetelstat Sodium n=60 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.
Phase 2 and Phase 3: Percentage of Participants Without Any RBC Transfusion During Any Consecutive 24-Weeks Period	24.6 percentage of participants Interval 14.13 to 37.76	28.0 percentage of participants Interval 20.1 to 36.98	3.3 percentage of participants Interval 0.41 to 11.53	—

SECONDARY outcome

Timeframe: Up to 5 years in Phase 2 and up to 3.7 years in Phase 3

Population: Phase 2: All Treated 8-week TI Responder Analysis Set included participants in the All Treated Analysis Set who achieved 8-week RBC TI. Phase 3: ITT 8-week TI Responder Analysis Set included all participants in the ITT Analysis Set who achieved 8-week RBC TI.

Time to 8-week RBC TI was defined as the interval from Study Day 1 to the first day of the first 8-week RBC TI period.

Outcome measures

Outcome measures
Measure	Phase 2: Imetelstat Sodium n=21 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Placebo n=47 Participants Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Imetelstat Sodium n=9 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.
Phase 2 and Phase 3: Time to the 8-Weeks RBC Transfusion Independence (TI)	8.29 weeks Interval 0.1 to 100.6	9.29 weeks Interval 0.1 to 64.7	8.29 weeks Interval 0.1 to 46.9	—

SECONDARY outcome

Timeframe: Up to 5 years in Phase 2 and up to 3.7 years in Phase 3

Population: Phase 2: All Treated 24-week TI Responder Analysis Set included participants in the All Treated Analysis Set who achieved 24-week RBC TI. Phase 3: ITT 24-week TI Responder Analysis Set included all participants in the ITT Analysis Set who achieved 24-week RBC TI.

Time to 24-week RBC TI was defined as the interval from Study Day 1 to the first day of the first 24-weeks RBC TI period.

Outcome measures

Outcome measures
Measure	Phase 2: Imetelstat Sodium n=14 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Placebo n=33 Participants Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Imetelstat Sodium n=2 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.
Phase 2 and Phase 3: Time to the 24-Weeks RBC TI	8.79 weeks Interval 3.3 to 100.6	8.43 weeks Interval 2.1 to 37.6	3.79 weeks Interval 0.3 to 7.3	—

SECONDARY outcome

Timeframe: Up to 5 years in Phase 2 and up to 3.7 years in Phase 3

Duration of RBC TI was defined as the first day of the longest RBC TI period to the date of the first RBC transfusion after the TI period started. The 95% CI was based on Kaplan-Meier product limit estimates.

Outcome measures

Outcome measures
Measure	Phase 2: Imetelstat Sodium n=21 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Placebo n=47 Participants Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Imetelstat Sodium n=9 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.
Phase 2 and Phase 3: Duration of RBC TI	69.6 weeks Interval 17.0 to 92.43	51.6 weeks Interval 26.86 to 80.43	13.3 weeks Interval 8.0 to 24.86	—

SECONDARY outcome

Timeframe: Up to 5 years in Phase 2 and up to 3.7 years in Phase 3

As per IWG Response Criteria 2006: HI-E was defined as a hemoglobin (Hb) increase by greater than or equal to (≥)1.5 grams per deciliter (g/dL) relevant reduction of units of RBC transfusions by an absolute number of at least 4 RBC transfusion units/8 weeks compared with the pretreatment transfusion number in the previous 8 weeks. Only RBC transfusions given for a Hb of less than or equal to (≤)9 g/dL pretreatment were counted in the RBC transfusion response evaluation. The 95% CI was calculated using Clopper-Pearson method. Percentages were rounded off to the nearest single decimal place.

Outcome measures

Outcome measures
Measure	Phase 2: Imetelstat Sodium n=57 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Placebo n=118 Participants Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Imetelstat Sodium n=60 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.
Phase 2 and Phase 3: Percentage of Participants With Hematologic Improvement Including Erythroid Response (HI-E) as Per International Working Group (IWG) Response Criteria 2006	61.4 percentage of participants Interval 47.57 to 74.0	63.6 percentage of participants Interval 54.2 to 72.22	51.7 percentage of participants Interval 38.39 to 64.77	—

SECONDARY outcome

Timeframe: Up to 5 years in Phase 2

Population: Phase 2: All Treated Analysis Set included all participants who received at least one dose of study drug.

As per the IWG Response Criteria 2006, CR was defined as Bone marrow: ≤5% myeloblasts with normal maturation of all cell lines; Peripheral blood (PB): Hb ≥11 g/dL; platelets ≥100 x 10\^9/dL; neutrophils ≥1.0 x 10\^9/liter; blasts: 0%. PR was defined as Bone marrow: ≤5% myeloblasts and decrease by ≥50% over pretreatment; cellularity and morphology not relevant. mCR was defined as Bone marrow: ≤5% myeloblasts and decreased by ≥50% over pre-treatment PB. Percentages were rounded off to the nearest single decimal place. All participants in Phase 2 were evaluated by the Investigator for CR/PR/mCR regardless of bone marrow blasts at baseline.

Outcome measures

Outcome measures
Measure	Phase 2: Imetelstat Sodium n=57 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Imetelstat Sodium Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.
Phase 2: Percentage of Participants With Complete Remission (CR), Partial Remission (PR), or Marrow Complete Remission (mCR) as Per International Working Group (IWG) Response Criteria 2006 as Assessed by the Investigator Percentage of participants with CR	8.8 percentage of participants	—	—	—
Phase 2: Percentage of Participants With Complete Remission (CR), Partial Remission (PR), or Marrow Complete Remission (mCR) as Per International Working Group (IWG) Response Criteria 2006 as Assessed by the Investigator Percentage of participants with PR	0 percentage of participants	—	—	—
Phase 2: Percentage of Participants With Complete Remission (CR), Partial Remission (PR), or Marrow Complete Remission (mCR) as Per International Working Group (IWG) Response Criteria 2006 as Assessed by the Investigator Percentage of participants with mCR	12.3 percentage of participants	—	—	—

SECONDARY outcome

Timeframe: Up to 3.7 years in Phase 3

Population: Phase 3: ITT Analysis Set included all participants randomized into the Phase 3 study. Overall number of participants analyzed is the number of participants with \>5% baseline bone marrow aspirate blasts per central pathology reviewer's assessment.

As per the IWG Response Criteria 2006, CR was defined as Bone marrow: ≤5% myeloblasts with normal maturation of all cell lines; PB: Hb ≥11 g/dL; platelets ≥100 x 10\^9/dL; neutrophils ≥1.0 x 10\^9/liter; blasts: 0%. PR was defined as Bone marrow: ≤5% myeloblasts and decrease by ≥50% over pretreatment; cellularity and morphology not relevant. mCR was defined as Bone marrow: ≤5% myeloblasts and decreased by ≥50% over pre-treatment PB. CR, PR and mCR were assessed by IRC in Phase 3 and participants were required to fit at least one of the following criteria (participants with \>5% baseline blasts per central pathology reviewer assessment; participants with CR, PR, mCR, or cytogenetic response as assessed by the investigator) and have at least one post-baseline assessment.

Outcome measures

Outcome measures
Measure	Phase 2: Imetelstat Sodium n=1 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Placebo n=1 Participants Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Imetelstat Sodium Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.
Phase 3: Percentage of Participants With CR, PR, or mCR as Per IWG Response Criteria 2006 as Assessed by the Independent Review Committee (IRC) Percentage of participants with CR	0 percentage of participants	0 percentage of participants	—	—
Phase 3: Percentage of Participants With CR, PR, or mCR as Per IWG Response Criteria 2006 as Assessed by the Independent Review Committee (IRC) Percentage of participants with PR	0 percentage of participants	0 percentage of participants	—	—
Phase 3: Percentage of Participants With CR, PR, or mCR as Per IWG Response Criteria 2006 as Assessed by the Independent Review Committee (IRC) Percentage of participants with mCR	0 percentage of participants	0 percentage of participants	—	—

SECONDARY outcome

Timeframe: Up to 6.6 years in Phase 2 and up to 4 years in Phase 3

OS was defined as the interval from Study Day 1 to death from any cause. Survival time of living participants was censored on the last date a participant is known to be alive or lost to follow-up. The Kaplan-Meier method was used to estimate overall survival.

Outcome measures

Outcome measures
Measure	Phase 2: Imetelstat Sodium n=57 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Placebo n=118 Participants Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Imetelstat Sodium n=60 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.
Phase 2 and Phase 3: Overall Survival (OS)	55.3 months Interval 39.16 to Upper limit of 95% CI was not estimable due to low number of participants with events.	40.4 months Interval 37.06 to Upper limit of 95% CI was not estimable due to low number of participants with events.	NA months Interval 32.16 to Median and upper limit of 95% CI were not estimable due to low number of participants with events.	—

SECONDARY outcome

Timeframe: Up to 6.6 years in Phase 2 and up to 4 years in Phase 3

Progression free survival was defined as the time interval from study Day 1 to the first date of disease progression or death from any cause, whichever occurs first. Disease progression as per IWG criteria was defined as: at least one of the following: at least 50 % decrement from maximum response levels in granulocytes or platelets; reduction in hemoglobin by ≥1.5 g/dL; transfusion dependence.

Outcome measures

Outcome measures
Measure	Phase 2: Imetelstat Sodium n=57 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Placebo n=118 Participants Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Imetelstat Sodium n=60 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.
Phase 2 and Phase 3: Progression Free Survival (PFS)	34.2 months Interval 25.1 to 39.29	NA months Interval 29.24 to Median and upper limit of 95% CI were not estimable due to low number of participants with events.	NA months Interval 16.72 to Median and upper limit of 95% CI were not estimable due to low number of participants with events.	—

SECONDARY outcome

Timeframe: Up to 6.6 years in Phase 2 and up to 4 years in Phase 3

Time to progression to AML was defined as the interval from Study Day 1 to the date of AML diagnosis. Participants who did not progress to AML and were still alive at the cutoff date for the analysis or who withdrew from the study (withdrawal of consent or lost to follow-up), data was censored at the date of the last disease evaluation.

Outcome measures

Outcome measures
Measure	Phase 2: Imetelstat Sodium n=57 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Placebo n=118 Participants Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Imetelstat Sodium n=60 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.
Phase 2 and Phase 3: Time to Progression to Acute Myeloid Leukemia (AML)	NA months Interval 41.36 to Median and upper limit of 95% CI were not estimable by Kaplan-Meir method due to low number of participants with events.	NA months Median, lower limit and upper limit of 95% CI were not estimable by Kaplan-Meir method due to low number of participants with events.	NA months Median, lower limit and upper limit of 95% CI were not estimable by Kaplan-Meir method due to low number of participants with events.	—

SECONDARY outcome

Timeframe: Up to 5 years in Phase 2 and up to 3.7 years in Phase 3

Amount of RBC transfusions for 8-week interval was defined as the total number of RBC transfusion units in a given 8-week interval during study. The best 8-week interval is a post-baseline 8-week interval where the participant had the fewest post-Study Day 1 RBC transfusion units. A valid 8-week period must start before the date of last dose of study drug + 30 days or end of treatment (EOT) visit whichever occurs first and ends before the first transfusion in post-treatment follow-up or the first day of subsequent anti-cancer therapy whichever occurs first.

Outcome measures

Outcome measures
Measure	Phase 2: Imetelstat Sodium n=57 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Placebo n=118 Participants Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Imetelstat Sodium n=60 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.
Phase 2 and Phase 3: Amount of RBC Transfusions in the Best 8-week Interval	3.0 number of RBC transfusions units Standard Deviation 3.48	3.1 number of RBC transfusions units Standard Deviation 3.62	3.4 number of RBC transfusions units Standard Deviation 2.13	—

SECONDARY outcome

Timeframe: Up to 5 years in Phase 2 and up to 3.7 years in Phase 3

Relative percent change in RBC transfusions per 8-week = (amount of RBC transfusions per 8-week - prior RBC transfusion burden) / prior RBC transfusion burden multiplied by 100%. Prior RBC transfusion burden was defined as the maximum number of RBC units transfused over any consecutive 8 weeks prior to study entry.

Outcome measures

Outcome measures
Measure	Phase 2: Imetelstat Sodium n=57 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Placebo n=118 Participants Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Imetelstat Sodium n=60 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.
Phase 2 and Phase 3: Percent Change in RBC Transfusions Relative to Prior Transfusion Burden	-62.5 percent change Standard Deviation 38.36	-57.75 percent change Standard Deviation 50.220	-51.01 percent change Standard Deviation 31.606	—

SECONDARY outcome

Timeframe: Up to 5 years in Phase 2 and up to 3.7 years in Phase 3

Percentage of participants who received any myeloid growth factors starting from Study Day 1 were reported. Percentages were rounded off to the nearest single decimal place.

Outcome measures

Outcome measures
Measure	Phase 2: Imetelstat Sodium n=57 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Placebo n=118 Participants Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Imetelstat Sodium n=60 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.
Phase 2 and Phase 3: Percentage of Participants Who Received Any Myeloid Growth Factors	33 percentage of participants	35.6 percentage of participants	5.0 percentage of participants	—

SECONDARY outcome

Timeframe: Up to 5 years in Phase 2 and up to 3.7 years in Phase 3

Population: Phase 2: All Treated Analysis Set included all participants who received at least one dose of study drug. Phase 3: ITT Analysis Set included all participants randomized into the Phase 3 study. Overall number of participants analyzed is the number of participants who had at least 1 dose of myeloid growth factors in Phase 2 and Phase 3.

Duration of myeloid growth factor administered starting from Study Day 1 was reported.

Outcome measures

Outcome measures
Measure	Phase 2: Imetelstat Sodium n=19 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Placebo n=42 Participants Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Imetelstat Sodium n=3 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.
Phase 2 and Phase 3: Duration of Myeloid Growth Factors Administration	1.43 weeks Interval 0.1 to 118.0	0.71 weeks Interval 0.1 to 12.9	3.14 weeks Interval 0.1 to 10.0	—

SECONDARY outcome

Timeframe: Pre-dose on Cycle 1 Day 1 and pre-dose on Day 1 of every 3 cycles from Cycle 4 up to Cycle 66 in Phase 2 and Cycle 34 in Phase 3 (each cycle length= 28 days)

Population: PK Parameter Analysis Set included all densely, and sparsely sampled participants who had received at least 1 dose of imetelstat sodium and who had sufficient data to calculate PK parameters for plasma imetelstat sodium. Overall number of participants analyzed signifies those participants who were evaluable for this outcome measure.

As pre-specified in the statistical analysis plan (SAP), participants in the imetelstat sodium arm group of Phase 2 and Phase 3 were pooled for pharmacokinetic (PK) data collection and analyses in this outcome measure. PK parameters were determined by population PK model.

Outcome measures

Outcome measures
Measure	Phase 2: Imetelstat Sodium n=170 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Imetelstat Sodium Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.
Phase 2 and Phase 3: Maximum Observed Plasma Concentration (Cmax)	89.5 micrograms per milliliter (mcg/mL) Standard Deviation 27.3	—	—	—

SECONDARY outcome

Timeframe: Cycle 1 (Days 1 to 28) (Cycle duration= 28 days)

As pre-specified in the statistical analysis plan (SAP), participants in the imetelstat sodium arm group of Phase 2 and Phase 3 were pooled for PK data collection and analyses in this outcome measure. PK parameters were determined by population PK model.

Outcome measures

Outcome measures
Measure	Phase 2: Imetelstat Sodium n=170 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Imetelstat Sodium Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.
Phase 2 and Phase 3: Area Under the Drug Concentration-Plasma Time Curve From Time Zero to Time 28 Days (AUC0-28d)	559 hourmicrograms per milliliter(hmcg/mL) Standard Deviation 43.2	—	—	—

SECONDARY outcome

Timeframe: Pre-dose on Cycle 1 Day 1 and pre-dose on Day 1 of every 3 cycles from Cycle 4 up to Cycle 66 in Phase 2 and Cycle 34 in Phase 3 (each cycle length= 28 days)

Population: The Pharmacodynamic (PD) Analysis Set included all participants who had at least one quantifiable post-dose determination on biomarker, efficacy or safety parameters as defined in the related Pharmacodynamics analysis plan. Overall number of participants analysed signifies those participants who were evaluable for this outcome measure.

As pre-specified in the SAP, participants in the imetelstat sodium arm group of Phase 2 and Phase 3 were pooled for immunogenicity data collection and analyses in this outcome measure. Percentages were rounded off to the nearest single decimal place.

Outcome measures

Outcome measures
Measure	Phase 2: Imetelstat Sodium n=166 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Imetelstat Sodium Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.
Phase 2 and Phase 3: Percentage of Participants With Anti-drug Antibodies (ADA) to Imetelstat Sodium	16.9 percentage of participants	—	—	—

SECONDARY outcome

Timeframe: Up to 3.7 years in Phase 3

Population: Phase 3: ITT Analysis Set included all participants randomized into the Phase 3 study.

Outpatient medical encounters included various sites of care: a) emergency room (ER) visits, b) hospital outpatient visits, c) home care visit, d) visit to lab, e) visit to doctor's office, f) other visits. Percentages were rounded off to the nearest single decimal place.

Outcome measures

Outcome measures
Measure	Phase 2: Imetelstat Sodium n=118 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Placebo n=60 Participants Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Imetelstat Sodium Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.
Phase 3: Medical Resource Utilization Assessed Based on Percentage of Participants With Outpatient Medical Encounters	39.0 percentage of participants	38.3 percentage of participants	—	—

SECONDARY outcome

Timeframe: Up to 3.7 years in Phase 3

Population: Phase 3: ITT Analysis Set included all participants randomized into the Phase 3 study. Overall number of participants analyzed is the number of participants who were hospitalized.

Hospitalization included any medical encounter defined as hospice, hospital inpatient department, and intensive care unit (ICU). Hospitalizations without end dates were not counted in the calculation of length of stay. If any participant had multiple readmissions, duration was calculated as the sum of all hospital stays.

Outcome measures

Outcome measures
Measure	Phase 2: Imetelstat Sodium n=43 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Placebo n=14 Participants Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Imetelstat Sodium Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.
Phase 3: Medical Resource Utilization Assessed Based on Duration of Hospitalization	8.0 days Interval 1.0 to 47.0	16.5 days Interval 1.0 to 75.0	—	—

SECONDARY outcome

Timeframe: Baseline, Cycle 1, Day 1: 0.5, 1, 2, 4, 6, and 8 hours post-dose (cycle length= 28 days)

Population: The QTc substudy analysis set included all participants who participated in QTc substudy and received at least one dose of study drug, with measurements at baseline as well as on-treatment with at least 1 post-dose time point with a ΔQTcF value. By-time Point Analysis Set included each post-baseline time point that had a non-missing change-from-baseline observation. Number analysed is the number of participants with data available for analysis at specified timepoints.

Baseline was defined as the mean of the measured ECG intervals collected at 3 time points (-1 hour, -0.5 hour, and 0 hour) prior to treatment administration on Cycle 1 Day 1 (Cycle length= 28 days)

Outcome measures

Outcome measures
Measure	Phase 2: Imetelstat Sodium n=29 Participants Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. Dose escalation to 9.4 mg/kg was allowed before Protocol Amendment 2.	Phase 3: Placebo n=16 Participants Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Imetelstat Sodium Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.
QTc Substudy: Change From Baseline in QT Interval by Fridericia's Correction Method (ΔQTcF) Change at 8 hr post-dose	2.3 milliseconds (ms) Standard Error 2.53	-3.4 milliseconds (ms) Standard Error 3.36	—	—
QTc Substudy: Change From Baseline in QT Interval by Fridericia's Correction Method (ΔQTcF) Change at 0.5 hr post-dose	4.2 milliseconds (ms) Standard Error 1.54	1.9 milliseconds (ms) Standard Error 2.09	—	—
QTc Substudy: Change From Baseline in QT Interval by Fridericia's Correction Method (ΔQTcF) Change at 1 hr post-dose	5.4 milliseconds (ms) Standard Error 1.47	0.4 milliseconds (ms) Standard Error 2.00	—	—
QTc Substudy: Change From Baseline in QT Interval by Fridericia's Correction Method (ΔQTcF) Change at 2 hr post-dose	5.5 milliseconds (ms) Standard Error 1.56	3.7 milliseconds (ms) Standard Error 2.12	—	—
QTc Substudy: Change From Baseline in QT Interval by Fridericia's Correction Method (ΔQTcF) Change at 4 hr post-dose	1.8 milliseconds (ms) Standard Error 2.43	1.1 milliseconds (ms) Standard Error 3.28	—	—
QTc Substudy: Change From Baseline in QT Interval by Fridericia's Correction Method (ΔQTcF) Change at 6 hr post-dose	1.7 milliseconds (ms) Standard Error 2.37	-1.1 milliseconds (ms) Standard Error 3.12	—	—

OTHER_PRE_SPECIFIED outcome

Timeframe: Up to approximately 3 years in the extension phase

An adverse event (AE) was any untoward medical occurrence in a clinical study participant administered a medicinal product. An AE does not necessarily have a causal relationship with the treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal finding), symptom, or disease temporally associated with the use of a medicinal product, whether or not related to that medicinal product. AEs included clinically significant vital signs measurements, clinical laboratory values and electrocardiograms (ECGs) changes.

Outcome measures

Outcome data not reported

OTHER_PRE_SPECIFIED outcome

Timeframe: Up to approximately 3 years in the extension phase

Outcome measures

Outcome data not reported

OTHER_PRE_SPECIFIED outcome

Timeframe: Up to approximately 3 years in the extension phase

Progression free survival will be assessed as the time interval from the end of the Phase 3 study until death, withdrawal of consent, study termination, or until a subject is lost to follow-up. As per IWG criteria disease progression is defined as: at least one of the following: at least 50 percent (%) decrement from maximum response levels in granulocytes or platelets; reduction in hemoglobin by greater than or equal to ≥1.5 g/dL; transfusion dependence.

Outcome measures

Outcome data not reported

Adverse Events

Phase 2: Imetelstat Sodium (No Dose Escalation)

Serious events: 26 serious events

Other events: 50 other events

Deaths: 24 deaths

Phase 2: Imetelstat Sodium (Escalated to 9.4 mg/kg)

Serious events: 1 serious events

Other events: 6 other events

Deaths: 3 deaths

Phase 3: Imetelstat Sodium

Serious events: 41 serious events

Other events: 117 other events

Deaths: 35 deaths

Phase 3: Placebo

Serious events: 13 serious events

Other events: 58 other events

Deaths: 15 deaths

QTc Substudy: Imetelstat Sodium

Serious events: 8 serious events

Other events: 33 other events

Deaths: 1 deaths

QTc Substudy: Crossover Imetelstat Sodium

Serious events: 3 serious events

Other events: 12 other events

Deaths: 0 deaths

QTc Substudy: Placebo

Serious events: 0 serious events

Other events: 13 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	Phase 2: Imetelstat Sodium (No Dose Escalation) n=50 participants at risk Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 2: Imetelstat Sodium (Escalated to 9.4 mg/kg) n=7 participants at risk Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) with dose escalation to 9.4 mg/kg allowed before Protocol Amendment 2, until death, lost to follow up, withdrawal of consent, or study termination, whichever occurs first.	Phase 3: Imetelstat Sodium n=118 participants at risk Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo n=59 participants at risk Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	QTc Substudy: Imetelstat Sodium n=35 participants at risk Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	QTc Substudy: Crossover Imetelstat Sodium n=14 participants at risk After a minimum of 2 treatment cycles (28-day cycle) if a participant had no significant change to pRBC transfusion burden or evidence of clinical benefit per Investigator, after discussion with the Sponsor the participant was crossed over from placebo to receive imetelstat sodium 7.5 mg/kg.	QTc Substudy: Placebo n=18 participants at risk Imetelstat sodium matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. If after a minimum of 2 treatment cycles a participant has no significant change to pRBC transfusion burden or evidence of clinical benefit per Investigator, after discussion with the Sponsor the participant, he/she may be permitted to start treatment with imetelstat sodium.
Infections and infestations Pneumonia	4.0% 2/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.5% 3/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 1/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Atypical pneumonia	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Bronchitis	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations COVID-19 pneumonia	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 2/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.1% 3/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Cellulitis	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Cellulitis staphylococcal	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Corynebacterium infection	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Dermo-hypodermitis	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Disseminated tuberculosis	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Escherichia bacteraemia	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Escherichia urinary tract infection	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Urosepsis	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Sepsis	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 2/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Urinary tract infection	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 2/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Clostridium difficile infection	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Enterococcal sepsis	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Erysipelas	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Escherichia sepsis	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Gastroenteritis clostridial	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Infection	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Neutropenic sepsis	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Pneumonia bacterial	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Pseudomembranous colitis	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Abscess limb	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	3.4% 2/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Arthritis bacterial	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 1/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Gastroenteritis	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 1/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Listeriosis	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 1/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Diarrhoea	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Gastric haemorrhage	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Gastrointestinal pain	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Inguinal hernia	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Intestinal haemorrhage	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Oesophageal varices haemorrhage	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Rectal haemorrhage	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Thrombosis mesenteric vessel	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Faecaloma	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Gastrointestinal disorder	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Gastrointestinal haemorrhage	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Diverticular perforation	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 1/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Small intestinal haemorrhage	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 1/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Injury, poisoning and procedural complications Femur fracture	6.0% 3/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 2/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 1/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Blood and lymphatic system disorders Cytopenia	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Injury, poisoning and procedural complications Brain contusion	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Injury, poisoning and procedural complications Extradural haematoma	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Injury, poisoning and procedural complications Hip fracture	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Injury, poisoning and procedural complications Spinal compression fracture	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Injury, poisoning and procedural complications Toxicity to various agents	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Injury, poisoning and procedural complications Humerus fracture	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 1/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Injury, poisoning and procedural complications Joint dislocation	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Blood and lymphatic system disorders Thrombocytopenia	4.0% 2/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Blood and lymphatic system disorders Anaemia	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.5% 3/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Blood and lymphatic system disorders Febrile neutropenia	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Blood and lymphatic system disorders Neutropenia	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Nervous system disorders Cerebrovascular accident	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Nervous system disorders Headache	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Nervous system disorders Neurodegenerative disorder	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Nervous system disorders Sciatica	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Nervous system disorders Syncope	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 2/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Cardiac disorders Cardiac failure	4.0% 2/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.5% 3/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Cardiac disorders Cardiac failure congestive	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 1/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Cardiac disorders Atrial fibrillation	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Cardiac disorders Angina pectoris	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Cardiac disorders Myocardial infarction	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Cardiac disorders Aortic valve incompetence	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 1/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Cardiac disorders Atrial flutter	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 1/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Cholangiocarcinoma	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Hepatic cancer	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Hepatocellular carcinoma	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Renal cell carcinoma	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Transitional cell carcinoma	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Bladder papilloma	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Lung neoplasm malignant	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Vascular disorders Haematoma	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Vascular disorders Hypertension	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Vascular disorders Hypertensive emergency	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Vascular disorders Peripheral ischaemia	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Vascular disorders Deep vein thrombosis	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Vascular disorders Hypertensive crisis	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Vascular disorders Aortic stenosis	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 1/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Vascular disorders Extremity necrosis	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 1/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Musculoskeletal and connective tissue disorders Back pain	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Musculoskeletal and connective tissue disorders Osteoarthritis	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Musculoskeletal and connective tissue disorders Arthralgia	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 1/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Musculoskeletal and connective tissue disorders Joint effusion	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 1/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Hepatobiliary disorders Biliary colic	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Hepatobiliary disorders Cholecystitis	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Metabolism and nutrition disorders Hyperglycaemia	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Metabolism and nutrition disorders Haemochromatosis	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 1/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Reproductive system and breast disorders Prostatitis	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Reproductive system and breast disorders Benign prostatic hyperplasia	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 1/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Respiratory, thoracic and mediastinal disorders Pleural effusion	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Respiratory, thoracic and mediastinal disorders Dyspnoea	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Respiratory, thoracic and mediastinal disorders Pulmonary oedema	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
General disorders Pyrexia	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 2/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
General disorders Asthenia	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
General disorders Influenza like illness	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Renal and urinary disorders Haematuria	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Renal and urinary disorders Kidney congestion	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Renal and urinary disorders Nephrolithiasis	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Product Issues Device occlusion	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Skin and subcutaneous tissue disorders Diabetic foot	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Blood and lymphatic system disorders Autoimmune haemolytic anaemia	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Blood and lymphatic system disorders Hypochromic anaemia	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Joint abscess	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Staphylococcal bacteraemia	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Staphylococcal sepsis	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Respiratory, thoracic and mediastinal disorders Lung infiltration	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Respiratory, thoracic and mediastinal disorders Pulmonary hypertension	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Nervous system disorders Cerebral infarction	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Injury, poisoning and procedural complications Subdural haematoma	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.

Other adverse events

Other adverse events
Measure	Phase 2: Imetelstat Sodium (No Dose Escalation) n=50 participants at risk Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 2: Imetelstat Sodium (Escalated to 9.4 mg/kg) n=7 participants at risk Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) with dose escalation to 9.4 mg/kg allowed before Protocol Amendment 2, until death, lost to follow up, withdrawal of consent, or study termination, whichever occurs first.	Phase 3: Imetelstat Sodium n=118 participants at risk Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	Phase 3: Placebo n=59 participants at risk Imetelstat sodium-matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	QTc Substudy: Imetelstat Sodium n=35 participants at risk Imetelstat sodium administered IV, at a starting dose of 7.5 mg/kg, every 4 weeks (on a 28-day cycle) until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first.	QTc Substudy: Crossover Imetelstat Sodium n=14 participants at risk After a minimum of 2 treatment cycles (28-day cycle) if a participant had no significant change to pRBC transfusion burden or evidence of clinical benefit per Investigator, after discussion with the Sponsor the participant was crossed over from placebo to receive imetelstat sodium 7.5 mg/kg.	QTc Substudy: Placebo n=18 participants at risk Imetelstat sodium matching placebo administered IV, every 4 weeks (on a 28-day cycle), until death, lost to follow-up, withdrawal of consent, or study termination whichever occurs first. If after a minimum of 2 treatment cycles a participant has no significant change to pRBC transfusion burden or evidence of clinical benefit per Investigator, after discussion with the Sponsor the participant, he/she may be permitted to start treatment with imetelstat sodium.
Blood and lymphatic system disorders Neutropenia	72.0% 36/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	28.6% 2/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	75.4% 89/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	8.5% 5/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	74.3% 26/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	57.1% 8/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	11.1% 2/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Blood and lymphatic system disorders Thrombocytopenia	66.0% 33/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	28.6% 2/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	75.4% 89/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	10.2% 6/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	71.4% 25/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	64.3% 9/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	16.7% 3/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Blood and lymphatic system disorders Anaemia	24.0% 12/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	19.5% 23/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	11.9% 7/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	8.6% 3/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Blood and lymphatic system disorders Leukopenia	22.0% 11/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	10.2% 12/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 1/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 5/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	21.4% 3/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
General disorders Pyrexia	20.0% 10/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	8.5% 10/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	11.9% 7/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
General disorders Oedema peripheral	14.0% 7/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	12.7% 15/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	13.6% 8/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	8.6% 3/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 2/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
General disorders Fatigue	10.0% 5/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	28.6% 2/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.6% 9/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	6.8% 4/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 5/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 2/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
General disorders Asthenia	8.0% 4/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	28.6% 2/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	17.8% 21/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	13.6% 8/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.7% 2/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
General disorders Influenza like illness	4.0% 2/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	28.6% 2/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.7% 2/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
General disorders Non-cardiac chest pain	6.0% 3/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Urinary tract infection	20.0% 10/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.9% 7/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	3.4% 2/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Nasopharyngitis	12.0% 6/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Bronchitis	12.0% 6/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Cellulitis	6.0% 3/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Upper respiratory tract infection	6.0% 3/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations COVID-19	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	16.1% 19/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	6.8% 4/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	11.4% 4/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
General disorders Chest pain	4.0% 2/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 2/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	8.5% 5/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Musculoskeletal and connective tissue disorders Back pain	20.0% 10/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	9.3% 11/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	8.5% 5/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.7% 2/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Musculoskeletal and connective tissue disorders Muscle spasms	10.0% 5/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Musculoskeletal and connective tissue disorders Muscular weakness	4.0% 2/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.7% 2/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Constipation	16.0% 8/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	8.5% 10/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	11.9% 7/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Musculoskeletal and connective tissue disorders Arthralgia	4.0% 2/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	8.5% 10/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 1/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Musculoskeletal and connective tissue disorders Myalgia	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.1% 6/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.1% 3/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Musculoskeletal and connective tissue disorders Pain in extremity	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	8.5% 5/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Diarrhoea	14.0% 7/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	28.6% 2/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	11.9% 14/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	11.9% 7/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	17.1% 6/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	21.4% 3/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Nausea	14.0% 7/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.6% 9/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.1% 3/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.7% 2/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	21.4% 3/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Vomiting	12.0% 6/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Abdominal pain	10.0% 5/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	6.8% 8/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	3.4% 2/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Abdominal pain upper	6.0% 3/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	28.6% 2/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 2/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	6.8% 4/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Gastritis	4.0% 2/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Investigations Alanine aminotransferase increased	14.0% 7/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	42.9% 3/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	11.0% 13/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	6.8% 4/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	17.1% 6/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	28.6% 4/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Investigations Aspartate aminotransferase increased	12.0% 6/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	28.6% 2/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	9.3% 11/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	6.8% 4/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	8.6% 3/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	21.4% 3/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Investigations Blood creatinine increased	8.0% 4/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 2/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.1% 3/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.7% 2/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Nervous system disorders Headache	22.0% 11/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	28.6% 2/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	12.7% 15/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.1% 3/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	8.6% 3/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Nervous system disorders Dizziness	8.0% 4/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.9% 7/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	6.8% 4/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.7% 2/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Metabolism and nutrition disorders Decreased appetite	8.0% 4/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.7% 2/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	28.6% 4/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Metabolism and nutrition disorders Hypokalaemia	6.0% 3/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Metabolism and nutrition disorders Hyponatraemia	6.0% 3/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Metabolism and nutrition disorders Hyperferritinaemia	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.1% 6/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	3.4% 2/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Metabolism and nutrition disorders Hyperkalaemia	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	6.8% 4/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Metabolism and nutrition disorders Iron overload	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.1% 3/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Respiratory, thoracic and mediastinal disorders Cough	12.0% 6/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 2/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.1% 3/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	8.6% 3/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 2/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Respiratory, thoracic and mediastinal disorders Dyspnoea	10.0% 5/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	9.3% 11/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	10.2% 6/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Respiratory, thoracic and mediastinal disorders Epistaxis	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.6% 9/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Vascular disorders Hypertension	10.0% 5/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Vascular disorders Haematoma	6.0% 3/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.9% 7/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Vascular disorders Hypotension	6.0% 3/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Renal and urinary disorders Haematuria	10.0% 5/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Injury, poisoning and procedural complications Contusion	6.0% 3/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.85% 1/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.1% 3/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Injury, poisoning and procedural complications Fall	6.0% 3/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Hepatobiliary disorders Hyperbilirubinaemia	10.0% 5/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	11.4% 4/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Hepatobiliary disorders Hepatomegaly	4.0% 2/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Cardiac disorders Atrial fibrillation	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.1% 6/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 1/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Skin and subcutaneous tissue disorders Pruritus	4.0% 2/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.9% 7/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	1.7% 1/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Blood and lymphatic system disorders Lymphopenia	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.7% 2/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Dry mouth	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Gastrointestinal pain	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Gastrooesophageal reflux disease	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Mouth ulceration	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Metabolism and nutrition disorders Hyperglycaemia	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	8.6% 3/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 2/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Metabolism and nutrition disorders Gout	4.0% 2/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
General disorders Gait disturbance	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
General disorders Infusion site discomfort	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
General disorders Pain	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
General disorders Peripheral swelling	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Investigations Gamma-glutamyltransferase increased	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 2/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Investigations Blood creatine phosphokinase increased	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Investigations Serum ferritin increased	4.0% 2/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Investigations Troponin T increased	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Musculoskeletal and connective tissue disorders Limb discomfort	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Gastroenteritis	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Pneumonia	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Nervous system disorders Burning sensation	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Nervous system disorders Hypoaesthesia	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Nervous system disorders Taste disorder	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Respiratory, thoracic and mediastinal disorders Dyspnoea exertional	4.0% 2/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Skin and subcutaneous tissue disorders Rash	4.0% 2/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Skin and subcutaneous tissue disorders Skin ulcer	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Skin and subcutaneous tissue disorders Hyperhidrosis	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Skin and subcutaneous tissue disorders Purpura	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Skin and subcutaneous tissue disorders Rash maculo-papular	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Skin and subcutaneous tissue disorders Urticaria	4.0% 2/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Hepatobiliary disorders Hypertransaminasaemia	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Cardiac disorders Palpitations	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Cardiac disorders Sinus tachycardia	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Eye disorders Vision blurred	4.0% 2/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Vascular disorders Flushing	4.0% 2/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Vascular disorders Hot flush	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Vascular disorders Peripheral artery stenosis	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Renal and urinary disorders Acute kidney injury	4.0% 2/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Renal and urinary disorders Pollakiuria	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Injury, poisoning and procedural complications Animal bite	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Injury, poisoning and procedural complications Skin abrasion	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Injury, poisoning and procedural complications Skin laceration	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Psychiatric disorders Confusional state	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Basal cell carcinoma	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	7.1% 1/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Stomatitis	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Dyspepsia	4.0% 2/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Abdominal discomfort	4.0% 2/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
General disorders Chills	4.0% 2/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Ear and labyrinth disorders Presbyacusis	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Ear and labyrinth disorders Ear congestion	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Psychiatric disorders Sleep disorder	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Skin and subcutaneous tissue disorders Melanoderma	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Respiratory, thoracic and mediastinal disorders Nasal congestion	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	2.9% 1/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	11.1% 2/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Wound infection	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Tooth infection	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Eye infection	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Investigations Weight decreased	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Investigations Cardiac murmur	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Musculoskeletal and connective tissue disorders Osteonecrosis	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	5.6% 1/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Skin and subcutaneous tissue disorders Dry skin	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Renal and urinary disorders Dysuria	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Infections and infestations Viral upper respiratory tract infection	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Musculoskeletal and connective tissue disorders Musculoskeletal pain	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Musculoskeletal and connective tissue disorders Flank pain	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Musculoskeletal and connective tissue disorders Groin pain	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Musculoskeletal and connective tissue disorders Muscle contracture	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Haematochezia	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Haemorrhoids	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Food poisoning	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Gastric antral vascular ectasia	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Gastric polyps	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Gastrointestinal angiectasia	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Gastrointestinal disorders Rectal haemorrhage	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Nervous system disorders Somnolence	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Vascular disorders Thrombosis	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Vascular disorders Vasculitis	0.00% 0/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.
Musculoskeletal and connective tissue disorders Neck Pain	2.0% 1/50 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	14.3% 1/7 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/118 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/59 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/35 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/14 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.	0.00% 0/18 • Adverse events: Up to 5 years in Phase 2; up to 3.7 years in Phase 3; up to 1.3 years in QTc substudy; All-cause mortality: Up to 6.6 years in Phase 2; up to 4 years in Phase 3; up to 1.6 years in QTc substudy Safety Analysis Set=all participants who received at least 1 dose of study drug. Safety data for Phase 2 arm has been reported separately for the participants without dose escalation and with dose escalation from 7.5 mg/kg to 9.4 mg/kg. QTc Substudy: Crossover arm includes AEs data after crossover from placebo to Imetelstat. Placebo arm included AE data for participants randomized to placebo prior to crossover.

Additional Information

Study Director

Geron Corp.

Phone: 650-473-7700

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee Consistent with Good Publication Practices and ICMJE guidelines, the sponsor shall have right to publish such primary (multicenter) data and information without approval from investigator. Investigator has right to publish study site-specific data after primary data published. If an investigator wishes to publish information from study, a copy of manuscript must be provided to sponsor for review at least 60 days before submission for publication or presentation.
Publication restrictions are in place

Restriction type: OTHER