MedPage Today in 2007.”,”detailed_bio”:”
“,”affiliation”:””,”credential”:””,”url_identifier”:”cb1064″,”avatar_url”:”https://assets.medpagetoday.net/media/images/author/charlesBankhead_188.jpg”,”avatar_alt_text”:”Charles Bankhead”,”twitter”:”https://twitter.com/CBankheadMPT”,”links”:{“signal”:””,”bluesky”:””,”website”:””,”linkedin”:””,”muckrack”:””},”has_author_page”:1,”byline”:”Senior Editor, MedPage Today”,”full_name”:”Charles Bankhead”,”title”:”Senior Editor, MedPage Today, “,”url”:”https://www.medpagetoday.com/people/cb1064/charles-bankhead”,”bluesky”:””}]” reviewedby date=”September 25, 2025″ updatedate=”September 25, 2025″ timetoread=”2 min read” articlehasdatawrapper breaking=”3″>
Oncology/Hematology
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Breast Cancer
— Imlunestrant improved PFS in progressive disease, no restriction on menopausal status
by Charles Bankhead, Senior Editor, MedPage Today
September 25, 2025 • 2 min read
The FDA approved the oral estrogen receptor antagonist imlunestrant (Inluriyo) for previously treated ESR1-mutated advanced/metastatic breast cancer, the agency announced Thursday.
The approval stipulates use in adults with estrogen receptor-positive/HER2-negative breast cancer that has progressed on at least one line of endocrine therapy.
Imlunestrant joins elacestrant (Orserdu) as the only FDA-approved oral therapies for ESR1-mutant breast cancer. In contrast to elacestrant, which is approved for use in postmenopausal women, imlunestrant’s approval is not limited by menopausal status.
“This represents an important advancement for patients with ESR1-mutated MBC [metastatic breast cancer], a mutation found in nearly half of patients who have taken hormone therapies, often contributing to treatment resistance,” said Komal Jhaveri, MD, of Memorial Sloan Kettering Cancer Center in New York City, in a statement from maker Eli Lilly. “With its demonstrated efficacy, tolerability profile, and oral administration, this therapy provides a meaningful alternative treatment option for this patient population.”
Jhaveri was a principal investigator in the EMBER-3 trial that supported FDA approval. The trial compared imlunestrant with standard endocrine therapy. In the subgroup of patients with ESR1-mutant breast cancer, the oral selective ER degrader (SERD) resulted in a median progression-free survival (PFS) of 5.5 months versus 3.8 months with endocrine therapy, representing a 38% reduction in the hazard for disease progression or death (95% CI 0.46-0.82, P<0.001).
Imlunestrant did not outperform endocrine therapy in the overall population, which included patients without ESR1 mutations. Median PFS was 5.6 months with imlunestrant versus 5.5 months with standard endocrine therapy.
In a secondary comparison, the SERD was evaluated in combination with the CDK4/6 inhibitor abemaciclib (Verzenio), which led to a median PFS of 9.4 months versus 5.5 months for imlunestrant alone (P<0.001).
“Imlunestrant, as monotherapy or combined with abemaciclib, provides an all-oral targeted therapy option after progression on endocrine therapy for patients with ER-positive, HER2-negative advanced breast cancer,” Jhaveri said last December at the San Antonio Breast Cancer Symposium.
In EMBER-3, the most common adverse events (≥10% of patients) were decreased hemoglobin, calcium, neutrophils, and platelets; increased liver enzymes, triglycerides, and cholesterol; and fatigue, diarrhea, nausea, constipation, and abdominal pain.
