Trial Outcomes & Findings for A Study to Learn About the Study Medicine (Elranatamab) in Participants With Multiple Myeloma That Has Come Back After Responding to Treatment or Has Not Responded to Treatment (NCT NCT05014412)

Last Updated: 2026-02-10

Results Overview

CRS: supraphysiologic response following any immune therapy that results in the activation or engagement of endogenous or infused T-cells and/or other immune effector cells. Symptoms must include fever at the onset, and may include hypotension, hypoxia and end organ dysfunction. As per ASTCT criteria, Grade (G) 1: fever (temperature \>=38 degree Celsius), hypotension and/or hypoxia none; G 2: fever, hypotension not requiring vasopressors, hypoxia requiring low-flow nasal cannula/ facemask or blow-by; G 3: fever, hypotension requiring a vasopressor with or without vasopressin, hypoxia requiring high-flow nasal cannula/ facemask, nonrebreather mask, or Venturi mask; G 4: fever, hypotension requiring multiple vasopressors (excluding vasopressin), hypoxia requiring positive pressure. Organ toxicities associated with CRS graded according to CTCAE v5.0. G 1: Mild, G 2: Moderate, G 3: severe, and G 4: life-threatening consequences; urgent intervention indicated. G 5: death related to AE.

Recruitment status

COMPLETED

Study phase

PHASE2

Target enrollment

86 participants

Primary outcome timeframe

Parts 1 and 2: Cycle 1 (28 days)

Results posted on

2026-02-10

Participant Flow

In this study Part 2C was exploratory and there was no participant enrolled in Part 2C as it was not conducted. A total of 86 participants with relapsed/ refractory multiple myeloma were enrolled in this study and 85 participants were treated.

Results are reported only for primary outcome measure and those secondary outcome measures whose analysis was final at primary completion date (15-June-2023). Remaining secondary outcome measures results would be reported once analysis is final.

Participant milestones

Participant milestones
Measure	Part 1 Participants received elranatamab 4 milligram (mg) on Cycle (C) 1 Day 1 (D) \[C1D1\] and 20 mg on C1D4 and then 76 mg every week (QW) for 6 cycles. Thereafter, participants with partial response (PR) or better response persisting for greater than equal to (\>=) 2 months on QW received 76 mg every 2 weeks (Q2W) and/or 116 mg or 152 mg every 4 weeks (Q4W) from C7 and onwards. One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.	Part 2A: Dose Level 1 Participants received elranatamab 4 mg on C1D1 and 20 mg on C1D4 and then 76 mg QW for 1 cycle. Thereafter, in dose level 1 received 116 mg Q2W for C2 to C6 and 116 mg Q4W from C7 and onwards (participants with PR or better response persisting for \>= 2 months on Q2W). One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.	Part 2A: Dose Level 2 Participants received elranatamab 4 mg on C1D1 and 20 mg on C1D4 and then 76 mg QW for 1 cycle. Thereafter, in dose level 2 participants received 152 mg Q2W for C2 to C6 and 152 mg Q4W from C7 and onwards (participants with PR or better response persisting for \>= 2 months on Q2W). One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.	Part 2B Participants received elranatamab 4 mg on C1D1 and 20 mg on C1D4 and then 76 mg QW for 1 cycle. Thereafter, participants were received 116 or 152 mg Q2W for C2 to 6 and 116 mg or 152 mg Q4W from C7 and onwards (participants with PR or better response persisting for \>=2 months on Q2W). One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.
Overall Study STARTED	33	12	11	29
Overall Study COMPLETED	0	0	0	0
Overall Study NOT COMPLETED	33	12	11	29

Reasons for withdrawal

Reasons for withdrawal
Measure	Part 1 Participants received elranatamab 4 milligram (mg) on Cycle (C) 1 Day 1 (D) \[C1D1\] and 20 mg on C1D4 and then 76 mg every week (QW) for 6 cycles. Thereafter, participants with partial response (PR) or better response persisting for greater than equal to (\>=) 2 months on QW received 76 mg every 2 weeks (Q2W) and/or 116 mg or 152 mg every 4 weeks (Q4W) from C7 and onwards. One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.	Part 2A: Dose Level 1 Participants received elranatamab 4 mg on C1D1 and 20 mg on C1D4 and then 76 mg QW for 1 cycle. Thereafter, in dose level 1 received 116 mg Q2W for C2 to C6 and 116 mg Q4W from C7 and onwards (participants with PR or better response persisting for \>= 2 months on Q2W). One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.	Part 2A: Dose Level 2 Participants received elranatamab 4 mg on C1D1 and 20 mg on C1D4 and then 76 mg QW for 1 cycle. Thereafter, in dose level 2 participants received 152 mg Q2W for C2 to C6 and 152 mg Q4W from C7 and onwards (participants with PR or better response persisting for \>= 2 months on Q2W). One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.	Part 2B Participants received elranatamab 4 mg on C1D1 and 20 mg on C1D4 and then 76 mg QW for 1 cycle. Thereafter, participants were received 116 or 152 mg Q2W for C2 to 6 and 116 mg or 152 mg Q4W from C7 and onwards (participants with PR or better response persisting for \>=2 months on Q2W). One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.
Overall Study Death	11	7	4	7
Overall Study Withdrawal by Subject	1	1	1	2
Overall Study Ongoing	21	4	6	20

Baseline Characteristics

A Study to Learn About the Study Medicine (Elranatamab) in Participants With Multiple Myeloma That Has Come Back After Responding to Treatment or Has Not Responded to Treatment

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Part 1 n=33 Participants Participants received elranatamab 4 mg on C1D1 and 20 mg on C1D4 and then 76 mg QW for 6 cycles. Thereafter, participants with PR or better response persisting for \>= 2 months on QW received 76 mg every Q2W and/or 116 mg or 152 mg Q4W from C7 and onwards. One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.	Part 2A: Dose Level 1 n=12 Participants Participants received elranatamab 4 mg on C1D1 and 20 mg on C1D4 and then 76 mg QW for 1 cycle. Thereafter, in dose level 1 received 116 mg Q2W for C2 to C6 and 116 mg Q4W from C7 and onwards (participants with PR or better response persisting for \>= 2 months on Q2W). One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.	Part 2A: Dose Level 2 n=11 Participants Participants received elranatamab 4 mg on C1D1 and 20 mg on C1D4 and then 76 mg QW for 1 cycle. Thereafter, in dose level 2 participants received 152 mg Q2W for C2 to C6 and 152 mg Q4W from C7 and onwards (participants with PR or better response persisting for \>= 2 months on Q2W). One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.	Part 2B n=29 Participants Participants received elranatamab 4 mg on C1D1 and 20 mg on C1D4 and then 76 mg QW for 1 cycle. Thereafter, participants were received 116 or 152 mg Q2W for C2 to 6 and 116 mg or 152 mg Q4W from C7 and onwards (participants with PR or better response persisting for \>=2 months on Q2W). One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.	Total n=85 Participants Total of all reporting groups
Age, Continuous	60.4 Years STANDARD_DEVIATION 10.14 • n=4 Participants	64.0 Years STANDARD_DEVIATION 8.75 • n=4 Participants	66.8 Years STANDARD_DEVIATION 11.12 • n=8 Participants	64.1 Years STANDARD_DEVIATION 8.08 • n=32 Participants	63.0 Years STANDARD_DEVIATION 9.53 • n=33 Participants
Sex: Female, Male Female	19 Participants n=4 Participants	4 Participants n=4 Participants	5 Participants n=8 Participants	15 Participants n=32 Participants	43 Participants n=33 Participants
Sex: Female, Male Male	14 Participants n=4 Participants	8 Participants n=4 Participants	6 Participants n=8 Participants	14 Participants n=32 Participants	42 Participants n=33 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	2 Participants n=4 Participants	0 Participants n=4 Participants	1 Participants n=8 Participants	2 Participants n=32 Participants	5 Participants n=33 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	30 Participants n=4 Participants	12 Participants n=4 Participants	9 Participants n=8 Participants	22 Participants n=32 Participants	73 Participants n=33 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	1 Participants n=4 Participants	0 Participants n=4 Participants	1 Participants n=8 Participants	5 Participants n=32 Participants	7 Participants n=33 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=4 Participants	0 Participants n=4 Participants	0 Participants n=8 Participants	0 Participants n=32 Participants	0 Participants n=33 Participants
Race (NIH/OMB) Asian	19 Participants n=4 Participants	5 Participants n=4 Participants	3 Participants n=8 Participants	8 Participants n=32 Participants	35 Participants n=33 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=4 Participants	0 Participants n=4 Participants	0 Participants n=8 Participants	0 Participants n=32 Participants	0 Participants n=33 Participants
Race (NIH/OMB) Black or African American	2 Participants n=4 Participants	0 Participants n=4 Participants	1 Participants n=8 Participants	1 Participants n=32 Participants	4 Participants n=33 Participants
Race (NIH/OMB) White	11 Participants n=4 Participants	6 Participants n=4 Participants	7 Participants n=8 Participants	17 Participants n=32 Participants	41 Participants n=33 Participants
Race (NIH/OMB) More than one race	0 Participants n=4 Participants	0 Participants n=4 Participants	0 Participants n=8 Participants	0 Participants n=32 Participants	0 Participants n=33 Participants
Race (NIH/OMB) Unknown or Not Reported	1 Participants n=4 Participants	1 Participants n=4 Participants	0 Participants n=8 Participants	3 Participants n=32 Participants	5 Participants n=33 Participants

PRIMARY outcome

Timeframe: Parts 1 and 2: Cycle 1 (28 days)

Population: Safety analysis set included all enrolled participants who received at least 1 dose of study intervention. Data for this outcome is presented for all participants in Part 1 and 2 of the study (combined) per study design, as all treatment groups utilized the same elranatamab priming regimen (4 mg on Day 1/20 mg on Day 4, followed by 76mg QW) during Cycle 1.

Outcome measures

Outcome measures
Measure	All Participants n=85 Participants All participants who were enrolled and treated in Part 1 and 2 of the study and evaluated for CRS.	Part 2A: Dose Level 2 Participants received elranatamab 4 mg on C1D1 and 20 mg on C1D4 and then 76 mg QW for 1 cycle. Thereafter, in dose level 2 participants received 152 mg Q2W for C2 to C6 and 152 mg Q4W from C7 and onwards (participants with PR or better response persisting for \>= 2 months on Q2W). One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.	Part 2A: Dose Level 2 Participants received elranatamab 4 mg on C1D1 and 20 mg on C1D4 and then 76 mg QW for 1 cycle. Thereafter, in dose level 2 participants received 152 mg Q2W for C2 to C6 and 152 mg Q4W from C7 and onwards (participants with PR or better response persisting for \>= 2 months on Q2W). One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.	Part 2B Participants received elranatamab 4 mg on C1D1 and 20 mg on C1D4 and then 76 mg QW for 1 cycle. Thereafter, participants were received 116 or 152 mg Q2W for C2 to 6 and 116 mg or 152 mg Q4W from C7 and onwards (participants with PR or better response persisting for \>=2 months on Q2W). One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.
Number of Participants With Grade 2 or Higher Cytokine Release Syndrome (CRS) During Cycle 1: Parts 1 and 2	12 Participants	—	—	—

SECONDARY outcome

Timeframe: Part 2A: 28 days starting from the first 116 or 152 mg dose

Population: All enrolled participants in Part 2A who received the planned 2 doses of 116 mg or 152 mg of study intervention during the DLT observation period or who received at least 1 dose of 116 mg or 152 mg of study intervention and experience DLT(s) during the DLT observation period. Here "Overall Number of Participants Analyzed" signifies the number of participants evaluable for this outcome measure. This outcome measure was not planned to be analyzed in Part 1 and Part 2B of the study.

Hematological: grade 4 neutropenia lasting \>5 days; febrile neutropenia; grade \>=3 neutropenia with infection; grade 4 thrombocytopenia; grade 3 thrombocytopenia with grade \>=2 bleeding. Non-hematological: grade \>=4 adverse events (AEs); grade 3 CRS (except CRS events: not been maximally treated or improved to grade \<=1 within 48 hours); grade 3 AEs (except: AEs attributed to a CRS event; grade 3 nausea, vomiting and diarrhea that improve to grade \<= 2 within 72 hours after maximal medical management has been initiated, grade 3 fatigue lasting \<1 week; grade 3 AEs that recover to baseline or grade 1 within 5 days); confirmed drug-induced liver injury meeting Hy's law criteria; grade 3-4 laboratory abnormalities; other clinically important or persistent AEs; Grade 3 injection site reaction. CTCAE version 5.0: Grade 1: Mild AE, Grade 2: Moderate, Grade 3: severe, and grade 4: life-threatening consequences; urgent intervention indicated. Grade 5: death related to AE.

Outcome measures

Outcome measures
Measure	All Participants n=7 Participants All participants who were enrolled and treated in Part 1 and 2 of the study and evaluated for CRS.	Part 2A: Dose Level 2 n=7 Participants Participants received elranatamab 4 mg on C1D1 and 20 mg on C1D4 and then 76 mg QW for 1 cycle. Thereafter, in dose level 2 participants received 152 mg Q2W for C2 to C6 and 152 mg Q4W from C7 and onwards (participants with PR or better response persisting for \>= 2 months on Q2W). One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.	Part 2A: Dose Level 2 Participants received elranatamab 4 mg on C1D1 and 20 mg on C1D4 and then 76 mg QW for 1 cycle. Thereafter, in dose level 2 participants received 152 mg Q2W for C2 to C6 and 152 mg Q4W from C7 and onwards (participants with PR or better response persisting for \>= 2 months on Q2W). One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.	Part 2B Participants received elranatamab 4 mg on C1D1 and 20 mg on C1D4 and then 76 mg QW for 1 cycle. Thereafter, participants were received 116 or 152 mg Q2W for C2 to 6 and 116 mg or 152 mg Q4W from C7 and onwards (participants with PR or better response persisting for \>=2 months on Q2W). One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.
Number of Participants With Dose Limiting Toxicities (DLTs): Part 2A	1 Participants	1 Participants	—	—

SECONDARY outcome

Timeframe: Day 1 of dosing up to 90 days post last dose (maximum treatment duration 25 cycles, follow up to 790 days)

Population: Safety analysis set included all enrolled participants who received at least 1 dose of study intervention.

An AE is any untoward medical occurrence in a participant or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An SAE is defined as any untoward medical occurrence that, at any dose, meets 1 or more of the criteria listed below: Results in death, requires inpatient hospitalization or prolongation of existing hospitalization, life-threatening, congenital anomaly/birth defect etc. A treatment-related AE was any untoward medical occurrence attributed to the study drug in a participant who received study drug. Relatedness to study drug was assessed by the investigator.

Outcome measures

Outcome measures
Measure	All Participants n=33 Participants All participants who were enrolled and treated in Part 1 and 2 of the study and evaluated for CRS.	Part 2A: Dose Level 2 n=12 Participants Participants received elranatamab 4 mg on C1D1 and 20 mg on C1D4 and then 76 mg QW for 1 cycle. Thereafter, in dose level 2 participants received 152 mg Q2W for C2 to C6 and 152 mg Q4W from C7 and onwards (participants with PR or better response persisting for \>= 2 months on Q2W). One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.	Part 2A: Dose Level 2 n=11 Participants Participants received elranatamab 4 mg on C1D1 and 20 mg on C1D4 and then 76 mg QW for 1 cycle. Thereafter, in dose level 2 participants received 152 mg Q2W for C2 to C6 and 152 mg Q4W from C7 and onwards (participants with PR or better response persisting for \>= 2 months on Q2W). One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.	Part 2B n=29 Participants Participants received elranatamab 4 mg on C1D1 and 20 mg on C1D4 and then 76 mg QW for 1 cycle. Thereafter, participants were received 116 or 152 mg Q2W for C2 to 6 and 116 mg or 152 mg Q4W from C7 and onwards (participants with PR or better response persisting for \>=2 months on Q2W). One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.
Number of Participants With Adverse Events (AEs) and Serious AEs (SAEs) [All Causalities and Treatment Related]: Parts 1 and 2 All cause: AE	33 Participants	12 Participants	11 Participants	29 Participants
Number of Participants With Adverse Events (AEs) and Serious AEs (SAEs) [All Causalities and Treatment Related]: Parts 1 and 2 All cause: SAE	23 Participants	11 Participants	8 Participants	21 Participants
Number of Participants With Adverse Events (AEs) and Serious AEs (SAEs) [All Causalities and Treatment Related]: Parts 1 and 2 Treatment related: AE	32 Participants	12 Participants	11 Participants	25 Participants
Number of Participants With Adverse Events (AEs) and Serious AEs (SAEs) [All Causalities and Treatment Related]: Parts 1 and 2 Treatment related: SAE	17 Participants	10 Participants	6 Participants	5 Participants

SECONDARY outcome

Timeframe: Day 1 of dosing up to 90 days post last dose (maximum treatment duration 25 cycles, follow up to 790 days)

Population: Safety analysis set included all enrolled participants who received at least 1 dose of study intervention.

An AE was any untoward medical occurrence in a participant or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. A treatment-related AE was any untoward medical occurrence attributed to the study drug in a participant who received study drug. Relatedness to study drug was assessed by the investigator. AEs were graded according to NCI CTCAE version 5.0 as Grade 1 indicates Mild AE, Grade 2 indicates Moderate AE, Grade 3 indicates severe AE, and grade 4 indicates life-threatening consequences; urgent intervention indicated. Grade 5 indicates death related to AE.

Outcome measures

Outcome measures
Measure	All Participants n=33 Participants All participants who were enrolled and treated in Part 1 and 2 of the study and evaluated for CRS.	Part 2A: Dose Level 2 n=12 Participants Participants received elranatamab 4 mg on C1D1 and 20 mg on C1D4 and then 76 mg QW for 1 cycle. Thereafter, in dose level 2 participants received 152 mg Q2W for C2 to C6 and 152 mg Q4W from C7 and onwards (participants with PR or better response persisting for \>= 2 months on Q2W). One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.	Part 2A: Dose Level 2 n=11 Participants Participants received elranatamab 4 mg on C1D1 and 20 mg on C1D4 and then 76 mg QW for 1 cycle. Thereafter, in dose level 2 participants received 152 mg Q2W for C2 to C6 and 152 mg Q4W from C7 and onwards (participants with PR or better response persisting for \>= 2 months on Q2W). One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.	Part 2B n=29 Participants Participants received elranatamab 4 mg on C1D1 and 20 mg on C1D4 and then 76 mg QW for 1 cycle. Thereafter, participants were received 116 or 152 mg Q2W for C2 to 6 and 116 mg or 152 mg Q4W from C7 and onwards (participants with PR or better response persisting for \>=2 months on Q2W). One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.
Number of Participants With Maximum Grade 3 or 4 and Grade 5 AEs [All Causalities and Treatment Related] Per National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) v5: Parts 1 and 2 All cause: Grades 3/4	26 Participants	9 Participants	6 Participants	20 Participants
Number of Participants With Maximum Grade 3 or 4 and Grade 5 AEs [All Causalities and Treatment Related] Per National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) v5: Parts 1 and 2 All cause: Grade 5	5 Participants	2 Participants	4 Participants	5 Participants
Number of Participants With Maximum Grade 3 or 4 and Grade 5 AEs [All Causalities and Treatment Related] Per National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) v5: Parts 1 and 2 Treatment related: Grades 3/4	23 Participants	10 Participants	9 Participants	16 Participants
Number of Participants With Maximum Grade 3 or 4 and Grade 5 AEs [All Causalities and Treatment Related] Per National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) v5: Parts 1 and 2 Treatment related: Grade 5	0 Participants	0 Participants	0 Participants	0 Participants

SECONDARY outcome

Timeframe: Day 1 of dosing up to 90 days post last dose (maximum treatment duration 25 cycles, follow up to 790 days)

Population: Safety analysis set included all enrolled participants who received at least 1 dose of study intervention.

CRS and ICANS were assessed according to ASTCT criteria. ASTCT for ICANS: Grade 1 \[immune effector cell-associated encephalopathy (ICE, overall score range 0-10, higher score = better condition) score 7-9, awakens spontaneously\]; Grade 2 \[ICE score 3-6, awakens to voice\]; Grade 3 \[ICE score 0-2, awakens only to tactile stimulus, any clinical seizure that resolves rapidly or non-convulsive seizures on EEG that resolve with intervention, focal/local oedema on neuroimaging\]; Grade 4 \[ICE 0 (unarousable and unable to perform ICE), Unarousable or requires vigorous or repetitive tactile stimuli to arouse. Stupor or coma, Life-threatening prolonged seizure (\>5 min); or repetitive clinical or electrical seizures without return to baseline in between, deep focal motor weakness such as hemiparesis or paraparesis, Diffuse cerebral oedema on neuroimaging; decerebrate or decorticate posturing; or cranial nerve VI (abducens nerve) palsy; or papilledema; or Cushing's triad\].

Outcome measures

Outcome measures
Measure	All Participants n=33 Participants All participants who were enrolled and treated in Part 1 and 2 of the study and evaluated for CRS.	Part 2A: Dose Level 2 n=12 Participants Participants received elranatamab 4 mg on C1D1 and 20 mg on C1D4 and then 76 mg QW for 1 cycle. Thereafter, in dose level 2 participants received 152 mg Q2W for C2 to C6 and 152 mg Q4W from C7 and onwards (participants with PR or better response persisting for \>= 2 months on Q2W). One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.	Part 2A: Dose Level 2 n=11 Participants Participants received elranatamab 4 mg on C1D1 and 20 mg on C1D4 and then 76 mg QW for 1 cycle. Thereafter, in dose level 2 participants received 152 mg Q2W for C2 to C6 and 152 mg Q4W from C7 and onwards (participants with PR or better response persisting for \>= 2 months on Q2W). One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.	Part 2B n=29 Participants Participants received elranatamab 4 mg on C1D1 and 20 mg on C1D4 and then 76 mg QW for 1 cycle. Thereafter, participants were received 116 or 152 mg Q2W for C2 to 6 and 116 mg or 152 mg Q4W from C7 and onwards (participants with PR or better response persisting for \>=2 months on Q2W). One cycle =28 days. Treatment continued until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or study termination.
Number of Participants With Adverse Events of Special Interest (AESI)- CRS and Immune Effector Cell-associated Neurotoxicity Syndrome (ICANS) [All Causalities and Treatment Related]: Parts 1 and 2 All cause: CRS	20 Participants	10 Participants	10 Participants	14 Participants
Number of Participants With Adverse Events of Special Interest (AESI)- CRS and Immune Effector Cell-associated Neurotoxicity Syndrome (ICANS) [All Causalities and Treatment Related]: Parts 1 and 2 All cause: ICANS	1 Participants	1 Participants	2 Participants	0 Participants
Number of Participants With Adverse Events of Special Interest (AESI)- CRS and Immune Effector Cell-associated Neurotoxicity Syndrome (ICANS) [All Causalities and Treatment Related]: Parts 1 and 2 Treatment related: CRS	20 Participants	10 Participants	10 Participants	13 Participants
Number of Participants With Adverse Events of Special Interest (AESI)- CRS and Immune Effector Cell-associated Neurotoxicity Syndrome (ICANS) [All Causalities and Treatment Related]: Parts 1 and 2 Treatment related: ICANS	1 Participants	1 Participants	2 Participants	0 Participants

SECONDARY outcome

Timeframe: Parts 1 and 2: From start of treatment to end of the study (approximately 3 years 7 months)

Hematology results were graded according to the NCI CTCAE version 5.0 for relevant parameters, Grade 1 indicates Mild AE, Grade 2 indicates Moderate AE, Grade 3 indicates severe AE, and grade 4 indicates life-threatening consequences; urgent intervention indicated, Grade 5 indicates death related to AE. Hematological measures included Hemoglobin, Platelet count, WBC count, Plasma cell count. Absolute: Neutrophils, Eosinophils, Monocytes, Basophils, Lymphocytes, Plasma cells etc.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Parts 1 and 2: From start of treatment to end of the study (approximately 3 years 7 months)

Clinical chemistry data included BUN (Blood urea nitrogen), Creatinine, Glucose (non-fasting), Total Calcium, Sodium, Potassium, Chloride, Magnesium, Phosphorus or Phosphates, Aspartate aminotransferase (AST), Alanine aminotransferase (ALT), Total bilirubin, Alkaline phosphatase, Albumin, Chloride, Total CO2 (bicarbonate), Total protein, Lactate dehydrogenase (LDH), Uric acid, Serum beta-2 microglobulin.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Parts 1 and 2: From start of treatment to end of the study (approximately 3 years 7 months)

Alanine aminotransferase, aspartate aminotransferase, Alkaline Phosphatase, and total bilirubin (TBILI) were used to assess possible drug induced liver toxicity.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Parts 1 and 2: From start of treatment to end of the study (approximately 3 years 7 months)

ORR: % of participants with objective response. stringent complete response (sCR):CR; ii) normal serum free light chain (FLC) ratio; absence of clonal cells in bone marrow biopsy (BMB)/ bone marrow aspirate (BMA) by immunohistochemistry or immunofluorescence. CR: negative immunofixation on serum and urine, disappearance of any soft tissue plasmacytomas and \<5% plasma cells in BMA. If the only measurable disease is by serum FLC levels, CR was normal serum FLC ratio of 0.26-1.65. VGPR:Serum and urine M-protein detectable by immunofixation but not on electrophoresis;\>=90% reduction in serum M-protein plus urine M-protein level \<100 mg/24 h; if only measurable disease is by serum FLC levels, VGPR:\>=90% decrease in difference between involved and uninvolved serum FLC levels; in addition if present at baseline, \>90% reduction compared to baseline in size of soft tissue plasmacytomas. PR:≥50% reduction of serum M-protein and reduction in 24 hours urinary M-protein by ≥90% or to \<200 mg/24 h.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Parts 1 and 2: From start of treatment to end of the study (approximately 3 years 7 months)

CRR was defined as the percentage of participants with a BOR of confirmed sCR/CR per IMWG response criteria as determined by investigator. sCR: i) CR; ii) normal serum FLC ratio and absence of clonal cells in BMB/BMA by immunohistochemistry or immunofluorescence (κ/λ ratio \<=4:1 or \>=1:2 for κ and λ participants, respectively, after counting \>=100 plasma cells; iii) if the only measurable disease was by serum FLC levels, sCR was defined as normal serum FLC ratio of 0.26 to 1.65 plus absence of clonal cells in BMB/BMA b by immunohistochemistry or immunofluorescence (κ/λ ratio \<=4:1 or \>=1:2 for κ and λ participants, respectively, after counting \>=100 plasma cells). CR: i) negative immunofixation on serum and urine, disappearance of any soft tissue plasmacytomas and \<5% plasma cells in BMA; ii) if the only measurable disease was by serum FLC levels, CR was defined as normal serum FLC ratio of 0.26 to 1.65 plus criteria (i).

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Parts 1 and 2: From start of treatment to end of the study (approximately 3 years 7 months)

Time to response was defined for participants with an objective response per IMWG criteria, as the time from the date of first dose to the first documentation of objective response that was subsequently confirmed.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Parts 1 and 2: From start of treatment to end of the study (approximately 3 years 7 months)

DOR: time from the first documentation of objective response, until confirmed PD, or death due to any cause, whichever occurred first. PD: Increase of \>=25% from lowest confirmed response value in any 1 or more of following: serum M-component (absolute increase must be \>=0.5 g/dL); serum M-protein increase \>=1 g/dL, if lowest M component was \>=5 g/dL; urine M-protein (absolute increase must be \>=200 mg/24 h). In participants without measurable serum and urine M-protein levels, difference between involved and uninvolved serum FLC levels (absolute increase must be \>10 mg/dL). In participants without measurable serum, urine M-protein levels and involved serum FLC levels, BM plasma-cell % irrespective of baseline status (must be \>=10%). Appearance of a new lesion, \>=50% increase from nadir in SPD of \>1 lesion, or \>=50% increase in longest diameter of a previous lesion \>1 cm in short axis. \>=50% increase in circulating plasma cells (minimum of 200 cells per mcL) if only measure of disease.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Parts 1 and 2: From start of treatment to end of the study (approximately 3 years 7 months)

DOCR was defined as the time from the first documentation of sCR or CR that was subsequently confirmed, until confirmed PD per IMWG criteria, or death due to any cause, whichever occurred first. sCR: i) CR; ii) normal serum FLC ratio and absence of clonal cells in BMB/BMA by immunohistochemistry or immunofluorescence (κ/λ ratio \<=4:1 or \>=1:2 for κ and λ participants, respectively, after counting \>=100 plasma cells; iii) if the only measurable disease was by serum FLC levels, sCR was defined as normal serum FLC ratio of 0.26 to 1.65 plus absence of clonal cells in BMB/BMA b by immunohistochemistry or immunofluorescence (κ/λ ratio \<=4:1 or \>=1:2 for κ and λ participants, respectively, after counting \>=100 plasma cells). CR: i) negative immunofixation on serum and urine, disappearance of any soft tissue plasmacytomas and \<5% plasma cells in BMA; ii) if the only measurable disease was by serum FLC levels, CR was defined as normal serum FLC ratio of 0.26 to 1.65 plus criteria (i).

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Parts 1 and 2: From start of treatment to end of the study (approximately 3 years 7 months)

PFS was defined as the time from the date of first dose until confirmed PD per IMWG criteria, or death due to any cause, whichever occurred first. Analysis was performed using Kaplan-Meier method. Participants with no PD event or death or who started a new anticancer therapy prior to an event or with an event after a gap of 2 or more missing disease assessments were censored on the date of last adequate disease assessment. Participants who did not have an adequate post-baseline disease assessment were censored on the date of first dose of study intervention unless death occurred on or before the time of the second planned disease assessment (\<=8 weeks after the date of first dose) in which case the death was considered an event.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Parts 1 and 2: From start of treatment to end of the study (approximately 3 years 7 months)

OS was defined as the time from the date of first dose until death due to any cause. If a participant was not known to have died, survival was censored at the date of last contact. Analysis was performed using Kaplan-Meier method.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Parts 1 and 2: From start of treatment to end of the study (approximately 3 years 7 months)

MRD negativity rate was defined as the percentage of participants with negative MRD (assessed by central laboratory) per IMWG sequencing criteria at any time from the date of first dose until the first documentation of confirmed PD, death or start of new anticancer therapy, whichever occurred first. Sequencing MRD negative included: 1) CR: negative immunofixation on serum and urine, disappearance of any soft tissue plasmacytomas and \<5% plasma cells in BMA. If the only measurable disease is by serum FLC levels, CR was defined as normal serum FLC ratio of 0.26 to 1.65; 2) Absence of clonal plasma cells by next generation sequencing (NGS) on BMA in which presence of a clone was defined as \<2 identical sequencing reads obtained after DNA sequencing of BMA using the LymphoSIGHT platform (or validated equivalent method) with a minimum sensitivity of 1 in 10\^5 nucleated cells.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Parts 1 and 2: Till study completion approximately 3 years 7 months

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Parts 1 and 2: From start of treatment to end of the study (approximately 3 years 7 months)

Outcome measures

Outcome data not reported

Adverse Events

Part 1

Serious events: 23 serious events

Other events: 33 other events

Deaths: 13 deaths

Part 2A: Dose Level 1

Serious events: 11 serious events

Other events: 12 other events

Deaths: 8 deaths

Part 2A: Dose Level 2

Serious events: 8 serious events

Other events: 10 other events

Deaths: 4 deaths

Part 2B

Serious events: 21 serious events

Other events: 28 other events

Deaths: 8 deaths

Serious adverse events

Other adverse events

Additional Information

Pfizer ClinicalTrials.gov Call Center

Pfizer Inc.

Phone: 1-800-718-1021

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee Pfizer has the right to review disclosures, requesting a delay of less than 60 days. Investigator will postpone single center publication until after disclosure of pooled data (all sites), less than 12 months from study completion/termination at all participating sites. Investigator may not disclose previously undisclosed confidential information other than study results.
Publication restrictions are in place

Restriction type: OTHER