A Study of Imlunestrant, Investigator's Choice of Endocrine Therapy, and Imlunestrant Plus Abemaciclib in Participants With ER+, HER2- Advanced Breast Cancer

Summary

The main purpose of this study is to measure how well imlunestrant works compared to standard hormone therapy, and how well imlunestrant with abemaciclib work compared to imlunestrant in participants with breast cancer that is estrogen receptor positive (ER+) and human epidermal receptor 2 negative (HER2-). Participants must have breast cancer that is advanced or has spread to another part of the body. Study participation could last up to 5 years.

Timeline

Start

2021-10-04

Primary completion

2024-06-24

Completion

2027-08

Outcome

Sources disagree · no verdict is set; each source's reading is shown below

registry analysis (superiority test); Arm A: Imlunestrant vs Arm B: Investigator's Choice of Endocrine Therapy; p = 0.1158; Hazard Ratio (HR) 0.867 reads as mixed primary results NCT04975308 ↗

registry analysis (superiority test); Arm C: Imlunestrant + Abemaciclib vs Arm A: Imlunestrant; p <0.0001; Hazard Ratio (HR) 0.569 reads as mixed primary results NCT04975308 ↗

registry analysis (superiority test); Arm A: Imlunestrant vs Arm B: Investigator's Choice of Endocrine Therapy; p = 0.0008; Hazard Ratio (HR) 0.617 reads as mixed primary results NCT04975308 ↗

release “EMBER-3 is the first Phase 3 trial to show benefit of combining an oral SERD with a CDK4/6 inhibitor” reads as mixed primary results lilly.com ↗

release “Imlunestrant significantly improved PFS versus SOC ET in patients with an ESR1 mutation.” reads as mixed primary results lilly.com ↗

release “In all patients, the median PFS was 5.6 months with imlunestrant versus 5.5 months with SOC ET” reads as mixed primary results lilly.com ↗

release “and did not reach statistical significance.” reads as mixed primary results lilly.com ↗

release “Imlunestrant-abemaciclib significantly improved PFS compared to imlunestrant in all patients” reads as mixed primary results lilly.com ↗

release “In the Phase 3 EMBER-3 trial, Inluriyo in combination with Verzenio doubled median progression-free survival compared to Inluriyo alone” reads as met primary endpoint lilly.com ↗

release “In an analysis of the primary outcome data, Inluriyo (imlunestrant) in combination with Verzenio (abemaciclib) doubled progression-free survival” reads as met primary endpoint lilly.com ↗

release “In the Phase 3 EMBER-3 trial, Inluriyo reduced the risk of progression or death by 38% versus ET.” reads as met primary endpoint lilly.com ↗

release “Among patients with ESR1-mutated MBC, Inluriyo significantly improved progression-free survival (PFS) versus fulvestrant or exemestane” reads as met primary endpoint lilly.com ↗

Publications

• Jhaveri KL, Neven P, Casalnuovo ML, Kim SB, Tokunaga E, Aftimos P, Saura C, O'Shaughnessy J, Harbeck N, Carey LA, Curigliano G, Llombart-Cussac A, Lim E, Garcia Tinoco ML, Sohn J, Mattar A, Zhang Q, Huang CS, Hung CC, Martinez Rodriguez JL, Ruiz Borrego M, Nakamura R, Pradhan KR, Cramer von Laue C, Barrett E, Cao S, Wang XA, Smyth LM, Bidard FC; EMBER-3 Study Group. Imlunestrant with or without Abemaciclib in Advanced Breast Cancer. N Engl J Med. 2025 Mar 27;392(12):1189-1202. doi: 10.1056/NEJMoa2410858. Epub 2024 Dec 11.

Drugs

Evaluation	Drug	Modality	Dose	Route
Subject	Abemaciclib	Small molecule	150 mg	Oral
Subject	Exemestane	Small molecule	25 mg	Oral
Subject	Fulvestrant	Small molecule	500 mg	Intramuscular
Subject	Imlunestrant	Small molecule	400 mg	Oral

Indications