European Commission approves Menarini Group’s ORSERDU (Elacestrant) for the treatment of Patients with ER+, HER2- Locally Advanced or Metastatic Breast Cancer with an activating ESR1 Mutation
The European Commission has approved ORSERDU (elacestrant) as a monotherapy for the treatment of postmenopausal women, and men, with estrogen receptor (ER)‑positive, HER2-negative, locally advanced or metastatic breast cancer (mBC) with an activating ESR1 mutation who have disease progression following at least one line of endocrine therapy including a CDK 4/6 inhibitor.
The European Commission’s approval follows the positive opinion of the Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA), which was issued in July 2023. With this approval, ORSERDU is the first and only therapy specifically indicated for the treatment of ER+, HER2- tumors that harbor ESR1 mutations. ESR1 mutations are acquired mutations that develop as a result of exposure to endocrine therapy, and they are found in up to 40% of patients with ER+, HER2- mBC. ESR1 mutations are a known driver of resistance to standard endocrine therapy, and until now, the tumors that harbor these mutations have been more difficult to treat.
The approval of ORSERDU is supported by data from the Phase 3 EMERALD trial, which demonstrated statistically significant progression-free survival (PFS) with elacestrant versus standard-of-care (SOC), defined as investigator’s choice of an approved endocrine monotherapy. The primary endpoints of the study were PFS in the overall patient population and in patients with ESR1 mutations. In the group of patients whose tumors had ESR1 mutations, elacestrant achieved a median PFS of 3.8 months vs 1.9 months on the SOC, and reduced the risk of progression or death by 45% (PFS HR=0.55, 95% CI: 0.39, 0.77) vs SOC.
A post hoc subgroup analysis of the EMERALD PFS results, which was presented at the San Antonio Breast Cancer Symposium (SABCS) 2022, demonstrated that the duration of prior CDK4/6i treatment was positively associated with longer PFS on elacestrant but not with SOC. For patients with ESR1 mutations who were treated with CDK4/6i for ≥12 months prior to randomization on EMERALD, elacestrant achieved a median PFS of 8.6 months versus 1.9 months on SOC, with a 59% reduction in the risk of progression or death (HR=0.41 95% CI: 0.26-0.63).³
Safety data were consistent with previously reported results. The most common (≥ 10%) adverse reactions with ORSERDU were nausea, triglycerides increased, cholesterol increased, vomiting, fatigue, dyspepsia, diarrhoea, calcium decreased, back pain, creatinine increased, arthralgia, sodium decreased, constipation, headache, hot flush, abdominal pain, anaemia, potassium decreased, and alanine aminotransferase increased. Important Safety Information for ORSERDU is provided below.
Stemline and its affiliates will commercialize the product within Europe.