Dr. Bidard on the FDA Approval of Elacestrant in ER+/HER2– Metastatic Breast Cancer

François-Clément Bidard, MD PhD, professor, medicine, Department of Medical Oncology, Institut Curie & UVSQ/Université Paris-Saclay; co-coordinator, Breast Cancer Research, Institut Curie, discusses the significance of the FDA approval of elacestrant (Orserdu) in patients with estrogen receptor (ER)–positive, HER2-negative metastatic breast cancer and key efficacy and safety data from the phase 3 EMERALD trial (NCT03778931).

On January 27, 2023, the FDA approved elacestrant in postmenopausal women or adult men with ER-positive, HER2-negative, ESR1-mutated advanced or metastatic breast cancer who have progressed on at least 1 line of endocrine therapy. The approval was based on the results of the EMERALD trial, which enrolled patients with ER-positive, HER2-negative disease who had failed 1 or 2 prior lines of endocrine therapy, including a mandatory CDK4/6 inhibitor and up to 1 prior line of chemotherapy in the advanced or metastatic setting. In total, 47.8% of patients in EMERALD had ESR1 mutations.

Dr. Bidard on the Efficacy of Elacestrant in HR+/HER2– Breast Cancer

This approval provides a new therapeutic option for patients in the ER-positive, HER2-negative, ESR1-mutated metastatic breast cancer population, which previously had an unmet need for effective treatment, Bidard says. Additionally, this is the first FDA approval for an oral selective estrogen receptor degrader (SERD) in breast cancer, Bidard emphasizes. Many other oral SERDs for breast cancer are in development, and the approval of elacestrant supports continued research with this class of drugs, Bidard says.

In EMERALD, treatment with elacestrant led to a median progression-free survival of 3.8 months vs 1.9 months with investigator’s choice of endocrine therapy in patients with ESR1 mutations, translating to a 45% reduction in the risk of disease progression or death. These findings demonstrate that patients who have previously received endocrine therapy now have the option to receive an effective agent that can further extend their survival, Bidard notes.

Dr. Bidard on the Safety Profile of Elacestrant

Findings from EMERALD published in the Journal of Clinical Oncology reported that elacestrant was well tolerated, which was expected, as endocrine therapies typically have limited toxicities, Bidard says. The main toxicities observed were low-grade nausea, vomiting, fatigue, and decreased appetite, Bidard explains. Overall, elacestrant is a safe drug to offer to patients, Bidard concludes.

Editor’s Note: Dr. Bidard has received research support from Pfizer, Prolynx, Menarini Silicon Biosystems, Merck KGaA, Rain Oncology, Roche, and Seagen; is a consultant for Astra-Zeneca, Caris, Daiichi-Sankyo, Exact Sciences, GE Healthcare, Gilead, GSK, Inatherys, Lilly, Menarini/Stemline, Novartis, Rain Oncology, Sanofi, and Seagen; is a speaker for Astra-Zeneca, Daiichi-Sankyo, Lilly, Menarini/Stemline, Pfizer, Rain Oncology, Sanofi, and Seagen; and is on the congresses for Astra-Zeneca, Pfizer, and Novartis.