Indianapolis, Indiana, September 18, 2026
Eli Lilly and Company has announced that the U.S. Food and Drug Administration (FDA) has approved Inluriyo® (imlunestrant) in combination with Verzenio® (abemaciclib) for the treatment of adults with estrogen receptor-positive (ER+), HER2-negative, ESR1-mutated advanced or metastatic breast cancer following progression on an endocrine-based therapy. The approval represents an important regulatory milestone for Lilly’s oncology portfolio and introduces a treatment combination designed to address tumors carrying ESR1 mutations, which can contribute to resistance to endocrine therapies. The FDA decision expands the role of imlunestrant, an oral selective estrogen receptor degrader, in a patient population with a specific molecular alteration associated with advanced breast cancer.
Lilly Advances Targeted Treatment for ESR1-Mutated Cancer
The FDA approval is based on results from the EMBER-3 Phase III clinical trial, which evaluated imlunestrant in patients with ER-positive, HER2-negative advanced or metastatic breast cancer. The study included patients whose disease had progressed during or after endocrine therapy and who had received at least one line of therapy in the advanced or metastatic setting. The trial investigated imlunestrant both as monotherapy and in combination with abemaciclib, providing data across different treatment approaches and patient subgroups. For patients with ESR1-mutated breast cancer, the molecular alteration can affect the estrogen receptor and contribute to continued tumor growth despite endocrine treatment.
The combination of Inluriyo and Verzenio is intended to provide dual targeting of the cancer biology by combining estrogen receptor degradation with CDK4/6 inhibition. Lilly said the approval provides an additional oral treatment option for eligible patients whose disease has progressed following prior endocrine-based treatment. The regulatory decision also reflects increasing emphasis on biomarker-driven oncology, where treatment selection can incorporate specific genetic characteristics of a patient’s tumor. Identifying ESR1 mutations may help clinicians determine whether patients are appropriate candidates for therapies designed to target estrogen receptor signaling.
Inluriyo and Verzenio Combination Shows Clinical Benefit
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The FDA’s decision was supported by results from EMBER-3, a randomized Phase III study evaluating imlunestrant in patients with ER-positive, HER2-negative advanced or metastatic breast cancer. The trial assessed progression-free survival (PFS) as a key efficacy measure and examined outcomes among patients with ESR1 mutations and other clinically relevant subgroups. In the combination arm, patients received imlunestrant together with abemaciclib, while the study also evaluated imlunestrant as a single agent. Lilly reported that the combination demonstrated a reduction in the risk of disease progression or death compared with imlunestrant alone in the overall study population. The results supported the use of the combination in patients whose disease had progressed following endocrine therapy.
The safety profile of the combination was consistent with the known safety profiles of the individual medicines. Neutropenia, diarrhea and fatigue were among the adverse reactions reported in patients receiving imlunestrant with abemaciclib. As with other cancer therapies, healthcare professionals are expected to consider individual patient characteristics, treatment history and potential adverse effects when selecting therapy.
Lilly Expands Oral Oncology Treatment Options
Inluriyo (imlunestrant) is an oral selective estrogen receptor degrader designed to target estrogen receptor signaling in hormone receptor-positive breast cancer. Verzenio (abemaciclib) is an oral CDK4/6 inhibitor that blocks proteins involved in cell-cycle progression. Their combination therefore targets breast cancer through complementary mechanisms. The FDA approval adds another option for patients with ESR1-mutated advanced or metastatic breast cancer, an area where acquired endocrine resistance remains an important clinical challenge. The approval also reinforces the growing role of molecular testing in advanced breast cancer treatment, particularly when genomic alterations can influence therapeutic decisions.
For Eli Lilly, the decision further strengthens its focus on oncology innovation and targeted cancer therapies. The company continues to evaluate imlunestrant across additional clinical settings and patient populations, with the broader development program designed to investigate its potential role in hormone receptor-positive breast cancer. The FDA approval of Inluriyo in combination with Verzenio therefore represents a significant development in the treatment landscape for eligible adults with ER-positive, HER2-negative, ESR1-mutated advanced or metastatic breast cancer. By combining estrogen receptor targeting and CDK4/6 inhibition, the regimen provides a biomarker-informed treatment approach for patients whose disease has progressed after endocrine-based therapy.
Source: Eli Lilly press release
