Trial Outcomes & Findings for Abemaciclib (LY2835219) Plus Fulvestrant Compared to Placebo Plus Fulvestrant in Previously Treated Breast Cancer (NCT NCT05169567)

Last Updated: 2026-01-16

Results Overview

PFS defined as the time from the date of randomization to the first evidence of disease progression as defined by response evaluation criteria in solid tumors (RECIST) v1.1 or death from any cause. Progressive Disease (PD) was at least a 20% increase in the sum of the diameters of target lesions, with reference being the smallest sum on study and an absolute increase of at least 5 mm, or unequivocal progression of non-target lesions, or 1 or more new lesions. If a participant does not have a complete baseline disease assessment, then the PFS time was censored at the date of randomization, regardless of whether or not objectively determined disease progression or death has been observed for the participant. If a participant was not known to have died or have objective progression as of the data inclusion cutoff date for the analysis, the PFS time was censored at the last adequate tumor assessment date.

Recruitment status

ACTIVE_NOT_RECRUITING

Study phase

PHASE3

Target enrollment

368 participants

Primary outcome timeframe

Randomization to the date of first documented progression of disease or death from any cause (Up to 21 Months)

Results posted on

2026-01-16

Participant Flow

Completers included participants who had an event (progressive disease or death) and participants who were off the treatment and were alive at study conclusion.

Participant milestones

Participant milestones
Measure	Arm A: Abemaciclib Plus Fulvestrant Abemaciclib 150 milligram (mg) administered orally twice daily (BID) on Days 1 to 28 of a 28-day cycle in combination with fulvestrant 500 mg administered intramuscularly (IM) on Days 1 and 15 of Cycle 1, then on Day 1 of Cycle 2 and beyond. Participants received treatment until discontinuation criteria were met.	Arm B: Placebo Plus Fulvestrant Placebo administered orally BID on Days 1 to 28 of a 28-day cycle in combination with fulvestrant 500 mg administered IM on Days 1 and 15 of Cycle 1, then on Day 1 of Cycle 2 and beyond. Participants received treatment until discontinuation criteria were met.
Overall Study STARTED	182	186
Overall Study Received at Least One Dose of Study Drug	181	185
Overall Study COMPLETED	40	37
Overall Study NOT COMPLETED	142	149

Reasons for withdrawal

Reasons for withdrawal
Measure	Arm A: Abemaciclib Plus Fulvestrant Abemaciclib 150 milligram (mg) administered orally twice daily (BID) on Days 1 to 28 of a 28-day cycle in combination with fulvestrant 500 mg administered intramuscularly (IM) on Days 1 and 15 of Cycle 1, then on Day 1 of Cycle 2 and beyond. Participants received treatment until discontinuation criteria were met.	Arm B: Placebo Plus Fulvestrant Placebo administered orally BID on Days 1 to 28 of a 28-day cycle in combination with fulvestrant 500 mg administered IM on Days 1 and 15 of Cycle 1, then on Day 1 of Cycle 2 and beyond. Participants received treatment until discontinuation criteria were met.
Overall Study On study treatment	116	128
Overall Study Lost to Follow-up	1	0
Overall Study Withdrawal by Subject	25	21

Baseline Characteristics

Abemaciclib (LY2835219) Plus Fulvestrant Compared to Placebo Plus Fulvestrant in Previously Treated Breast Cancer

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Arm A: Abemaciclib Plus Fulvestrant n=182 Participants Abemaciclib 150 mg administered orally BID on Days 1 to 28 of a 28-day cycle in combination with fulvestrant 500 mg administered IM on Days 1 and 15 of Cycle 1, then on Day 1 of Cycle 2 and beyond. Participants received treatment until discontinuation criteria were met.	Arm B: Placebo Plus Fulvestrant n=186 Participants Placebo administered orally BID on Days 1 to 28 of a 28-day cycle in combination with fulvestrant 500 mg administered IM on Days 1 and 15 of Cycle 1, then on Day 1 of Cycle 2 and beyond. Participants received treatment until discontinuation criteria were met.	Total n=368 Participants Total of all reporting groups
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=9 Participants	0 Participants n=6 Participants	0 Participants n=9 Participants
Age, Continuous	58.00 years STANDARD_DEVIATION 12.15 • n=9 Participants	59.60 years STANDARD_DEVIATION 12.16 • n=6 Participants	58.80 years STANDARD_DEVIATION 12.17 • n=9 Participants
Sex: Female, Male Female	180 Participants n=9 Participants	185 Participants n=6 Participants	365 Participants n=9 Participants
Sex: Female, Male Male	2 Participants n=9 Participants	1 Participants n=6 Participants	3 Participants n=9 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	28 Participants n=9 Participants	27 Participants n=6 Participants	55 Participants n=9 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	135 Participants n=9 Participants	143 Participants n=6 Participants	278 Participants n=9 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	19 Participants n=9 Participants	16 Participants n=6 Participants	35 Participants n=9 Participants
Race (NIH/OMB) American Indian or Alaska Native	3 Participants n=9 Participants	2 Participants n=6 Participants	5 Participants n=9 Participants
Race (NIH/OMB) Asian	21 Participants n=9 Participants	26 Participants n=6 Participants	47 Participants n=9 Participants
Race (NIH/OMB) Black or African American	6 Participants n=9 Participants	3 Participants n=6 Participants	9 Participants n=9 Participants
Race (NIH/OMB) White	140 Participants n=9 Participants	143 Participants n=6 Participants	283 Participants n=9 Participants
Race (NIH/OMB) More than one race	0 Participants n=9 Participants	0 Participants n=6 Participants	0 Participants n=9 Participants
Race (NIH/OMB) Unknown or Not Reported	12 Participants n=9 Participants	12 Participants n=6 Participants	24 Participants n=9 Participants
Region of Enrollment Argentina	19 Participants n=9 Participants	20 Participants n=6 Participants	39 Participants n=9 Participants
Region of Enrollment Belgium	7 Participants n=9 Participants	5 Participants n=6 Participants	12 Participants n=9 Participants
Region of Enrollment Czechia	1 Participants n=9 Participants	1 Participants n=6 Participants	2 Participants n=9 Participants
Region of Enrollment Denmark	1 Participants n=9 Participants	2 Participants n=6 Participants	3 Participants n=9 Participants
Region of Enrollment France	11 Participants n=9 Participants	10 Participants n=6 Participants	21 Participants n=9 Participants
Region of Enrollment Greece	8 Participants n=9 Participants	4 Participants n=6 Participants	12 Participants n=9 Participants
Region of Enrollment Hungary	7 Participants n=9 Participants	9 Participants n=6 Participants	16 Participants n=9 Participants
Region of Enrollment Israel	12 Participants n=9 Participants	11 Participants n=6 Participants	23 Participants n=9 Participants
Region of Enrollment Italy	16 Participants n=9 Participants	11 Participants n=6 Participants	27 Participants n=9 Participants
Region of Enrollment Mexico	5 Participants n=9 Participants	4 Participants n=6 Participants	9 Participants n=9 Participants
Region of Enrollment Poland	2 Participants n=9 Participants	1 Participants n=6 Participants	3 Participants n=9 Participants
Region of Enrollment South Korea	10 Participants n=9 Participants	10 Participants n=6 Participants	20 Participants n=9 Participants
Region of Enrollment Spain	27 Participants n=9 Participants	31 Participants n=6 Participants	58 Participants n=9 Participants
Region of Enrollment Taiwan	11 Participants n=9 Participants	14 Participants n=6 Participants	25 Participants n=9 Participants
Region of Enrollment Turkey	17 Participants n=9 Participants	25 Participants n=6 Participants	42 Participants n=9 Participants
Region of Enrollment United States	28 Participants n=9 Participants	28 Participants n=6 Participants	56 Participants n=9 Participants

PRIMARY outcome

Timeframe: Randomization to the date of first documented progression of disease or death from any cause (Up to 21 Months)

Population: All randomized participants (including censored). Censored participants: Abemaciclib plus fulvestrant (n = 65), Placebo plus fulvestrant (n = 45).

Outcome measures

Outcome measures
Measure	Arm A: Abemaciclib Plus Fulvestrant n=182 Participants Abemaciclib 150 mg administered orally BID on Days 1 to 28 of a 28-day cycle in combination with fulvestrant 500 mg administered IM on Days 1 and 15 of Cycle 1, then on Day 1 of Cycle 2 and beyond. Participants received treatment until discontinuation criteria were met.	Arm B: Placebo Plus Fulvestrant n=186 Participants Placebo administered orally BID on Days 1 to 28 of a 28-day cycle in combination with fulvestrant 500 mg administered IM on Days 1 and 15 of Cycle 1, then on Day 1 of Cycle 2 and beyond. Participants received treatment until discontinuation criteria were met.
Progression-Free Survival (PFS)	6 Months Interval 5.6 to 8.1	5.3 Months Interval 3.7 to 5.6

SECONDARY outcome

Timeframe: Randomization to the date of first documented progression of disease or death from any cause (Up to 22 Months)

Population: All randomized participants.

PFS is defined as the time from the date of randomization to the earliest date of disease progression determined by blinded independent central review (BICR) or death from any cause, whichever occurs first.

Outcome measures

Outcome measures
Measure	Arm A: Abemaciclib Plus Fulvestrant n=182 Participants Abemaciclib 150 mg administered orally BID on Days 1 to 28 of a 28-day cycle in combination with fulvestrant 500 mg administered IM on Days 1 and 15 of Cycle 1, then on Day 1 of Cycle 2 and beyond. Participants received treatment until discontinuation criteria were met.	Arm B: Placebo Plus Fulvestrant n=186 Participants Placebo administered orally BID on Days 1 to 28 of a 28-day cycle in combination with fulvestrant 500 mg administered IM on Days 1 and 15 of Cycle 1, then on Day 1 of Cycle 2 and beyond. Participants received treatment until discontinuation criteria were met.
Progression Free Survival (PFS) Determined by Blinded Independent Central Review (BICR)	12.9 Months Interval 9.5 to Upper limit of 95% CI was not estimable due to insufficient number of events.	5.6 Months Interval 3.9 to 7.7

SECONDARY outcome

Timeframe: Randomization until measured progressive disease (Up to 22 Months)

Population: All randomized participants.

ORR is the best overall tumor response of CR or PR as classified by the investigator according to the Response Evaluation Criteria In Solid Tumors (RECIST v1.1). CR is a disappearance of all target and non-target lesions and normalization of tumor marker level. PR is an at least 30% decrease in the sum of the diameters of target lesions (taking as reference the baseline sum diameter) without progression of non-target lesions or appearance of new lesions.

Outcome measures

Outcome measures
Measure	Arm A: Abemaciclib Plus Fulvestrant n=182 Participants Abemaciclib 150 mg administered orally BID on Days 1 to 28 of a 28-day cycle in combination with fulvestrant 500 mg administered IM on Days 1 and 15 of Cycle 1, then on Day 1 of Cycle 2 and beyond. Participants received treatment until discontinuation criteria were met.	Arm B: Placebo Plus Fulvestrant n=186 Participants Placebo administered orally BID on Days 1 to 28 of a 28-day cycle in combination with fulvestrant 500 mg administered IM on Days 1 and 15 of Cycle 1, then on Day 1 of Cycle 2 and beyond. Participants received treatment until discontinuation criteria were met.
Objective Response Rate (ORR): Percentage of Participants Who Achieved a Best Overall Response (BOR) of Complete Response (CR) or Partial Response (PR)	24 Percentage of participants	10 Percentage of participants

Adverse Events

Arm A: Abemaciclib Plus Fulvestrant

Serious events: 44 serious events

Other events: 173 other events

Deaths: 40 deaths

Arm B: Placebo Plus Fulvestrant

Serious events: 20 serious events

Other events: 131 other events

Deaths: 37 deaths

Serious adverse events

Other adverse events

Additional Information

Chief Medical Officer

Eli Lilly and Company

Phone: 08005455979

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place

Restriction type: LTE60

Measure	Arm A: Abemaciclib Plus Fulvestrant n=181 participants at risk Abemaciclib 150 mg administered orally BID on Days 1 to 28 of a 28-day cycle in combination with fulvestrant 500 mg administered IM on Days 1 and 15 of Cycle 1, then on Day 1 of Cycle 2 and beyond. Participants received treatment until discontinuation criteria were met.	Arm B: Placebo Plus Fulvestrant n=185 participants at risk Placebo administered orally BID on Days 1 to 28 of a 28-day cycle in combination with fulvestrant 500 mg administered IM on Days 1 and 15 of Cycle 1, then on Day 1 of Cycle 2 and beyond. Participants received treatment until discontinuation criteria were met.
General disorders Oedema peripheral	5.5% 10/181 • Number of events 10 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	2.2% 4/185 • Number of events 4 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
General disorders Pyrexia	6.6% 12/181 • Number of events 13 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	2.2% 4/185 • Number of events 4 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Gastrointestinal disorders Abdominal pain	22.7% 41/181 • Number of events 46 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	16.2% 30/185 • Number of events 40 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Gastrointestinal disorders Constipation	6.6% 12/181 • Number of events 15 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	6.5% 12/185 • Number of events 12 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Gastrointestinal disorders Diarrhoea	74.6% 135/181 • Number of events 307 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	16.8% 31/185 • Number of events 46 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Gastrointestinal disorders Nausea	32.6% 59/181 • Number of events 75 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	18.4% 34/185 • Number of events 43 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Gastrointestinal disorders Vomiting	19.3% 35/181 • Number of events 46 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	5.9% 11/185 • Number of events 13 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
General disorders Fatigue	32.6% 59/181 • Number of events 66 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	23.2% 43/185 • Number of events 52 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Blood and lymphatic system disorders Anaemia	34.8% 63/181 • Number of events 87 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	14.6% 27/185 • Number of events 36 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Blood and lymphatic system disorders Leukopenia	17.7% 32/181 • Number of events 48 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	3.2% 6/185 • Number of events 6 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Blood and lymphatic system disorders Lymphopenia	8.8% 16/181 • Number of events 30 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	2.2% 4/185 • Number of events 6 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Blood and lymphatic system disorders Neutropenia	40.3% 73/181 • Number of events 130 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	3.2% 6/185 • Number of events 8 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Blood and lymphatic system disorders Thrombocytopenia	18.2% 33/181 • Number of events 47 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	5.9% 11/185 • Number of events 12 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Infections and infestations Covid-19	7.7% 14/181 • Number of events 15 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	4.9% 9/185 • Number of events 9 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Infections and infestations Urinary tract infection	7.7% 14/181 • Number of events 18 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	2.2% 4/185 • Number of events 4 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Investigations Alanine aminotransferase increased	12.7% 23/181 • Number of events 25 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	10.3% 19/185 • Number of events 25 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Investigations Aspartate aminotransferase increased	14.9% 27/181 • Number of events 34 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	10.8% 20/185 • Number of events 25 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Investigations Blood alkaline phosphatase increased	6.6% 12/181 • Number of events 14 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	6.5% 12/185 • Number of events 14 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Investigations Blood creatinine increased	11.0% 20/181 • Number of events 28 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	2.2% 4/185 • Number of events 4 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Investigations Gamma-glutamyltransferase increased	8.8% 16/181 • Number of events 21 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	6.5% 12/185 • Number of events 13 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Investigations Weight decreased	6.1% 11/181 • Number of events 11 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	0.54% 1/185 • Number of events 1 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Metabolism and nutrition disorders Decreased appetite	18.2% 33/181 • Number of events 40 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	6.5% 12/185 • Number of events 12 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Metabolism and nutrition disorders Hypokalaemia	8.8% 16/181 • Number of events 22 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	2.2% 4/185 • Number of events 7 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Musculoskeletal and connective tissue disorders Arthralgia	11.6% 21/181 • Number of events 28 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	12.4% 23/185 • Number of events 24 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Musculoskeletal and connective tissue disorders Back pain	5.0% 9/181 • Number of events 9 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	9.2% 17/185 • Number of events 19 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Musculoskeletal and connective tissue disorders Bone pain	2.2% 4/181 • Number of events 4 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	5.4% 10/185 • Number of events 13 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Musculoskeletal and connective tissue disorders Pain in extremity	5.5% 10/181 • Number of events 10 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	7.0% 13/185 • Number of events 15 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Nervous system disorders Dizziness	7.7% 14/181 • Number of events 16 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	7.0% 13/185 • Number of events 14 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Nervous system disorders Headache	8.8% 16/181 • Number of events 17 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	8.1% 15/185 • Number of events 17 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Nervous system disorders Neuropathy	2.2% 4/181 • Number of events 4 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	6.5% 12/185 • Number of events 17 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Psychiatric disorders Insomnia	6.6% 12/181 • Number of events 12 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	4.3% 8/185 • Number of events 8 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Respiratory, thoracic and mediastinal disorders Cough	10.5% 19/181 • Number of events 25 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	6.5% 12/185 • Number of events 12 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Respiratory, thoracic and mediastinal disorders Dyspnoea	8.3% 15/181 • Number of events 18 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	3.2% 6/185 • Number of events 7 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Skin and subcutaneous tissue disorders Rash	8.8% 16/181 • Number of events 18 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	3.8% 7/185 • Number of events 7 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.
Vascular disorders Hot flush	7.2% 13/181 • Number of events 14 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.	6.5% 12/185 • Number of events 12 • Baseline up to 22 months All participants who received at least one dose of the study drug, regardless of their eligibility for the study.