The regulatory decision to approve elacestrant in European patients with estrogen receptor–positive, HER2-negative locally advanced or metastatic breast cancer and an activating ESR1 mutation was based on data from the phase 3 EMERALD study.
The European Commission has granted approval to elacestrant (Orserdu) for those with ESR1-mutant, estrogen receptor (ER)–positive, HER2-negative locally advanced or metastatic breast cancer who progressed after a minimum of 1 line of endocrine therapy including a CDK4/6 inhibitor, according to a press release from the Menarini Group.1
The approval was based on findings from the phase 3 EMERALD study (NCT03778931) in which patients treated with elacestrant experienced a statistically significant progression-free survival benefit over standard of care at a median of 3.8 months and 1.9 months, respectively. This translated to a 45% reduction in risk of progression or death (HR, 0.55; 95% CI, 0.39-0.77).
Frequent adverse effects associated with elacestrant include nausea, triglyceride increase, cholesterol increase, vomiting, fatigue, dyspepsia, diarrhea, calcium decrease, back pain, creatinine increase, arthralgia, sodium decrease, constipation, headache, hot flush, abdominal pain, anemia, potassium decrease, and alanine aminotransferase increase.
“With a significant number of patients [with ER–positive, HER2-negative disease] ultimately developing ESR1 mutations at some point in their metastatic journey, it is important to test for ESR1 each time a patient [with metastatic breast cancer] experiences disease progression, to understand what is fueling their [disease],” Giuseppe Curigliano, MD, PhD, professor of Medical Oncology at the University of Milano and the head of the Division of Early Drug Development at the European Institute of Oncology, IRCCS, Italy, said in the press release. “Today’s approval gives us the first-ever treatment option that directly acts against the very mutations that make this form of breast cancer more difficult to treat, and provides hope to our patients and their families.”
Elacestrant was approved by the FDA in January 2023 for those with ER–positive, HER2-negative, ESR1-mutant advanced or metastatic breast cancer following a minimum of one line of therapy along with the Guardant 360 CDx assay.2 This decision was also based on data from the phase 3 EMERALD study.