The FDA has approved Stemline Therapeutics’ Orserdu (elacestrant) as the first treatment for postmenopausal women or adult men with ER-positive, HER2-negative, ESR1-mutated advanced or metastatic breast cancer who have experienced disease progression after at least one line of endocrine therapy.

Orserdu is an estrogen receptor antagonist that blocks estrogen activity.

Orserdu received Priority Review and Fast Track designations from the FDA based on the results of a phase 3 trial that demonstrated statistically significant progression-free survival (PFS) with elacestrant vs. standard of care endocrine monotherapy (fulvestrant, letrozole, anastrozole, exemestane), meeting both primary endpoints in all patients and in those patients whose tumors harbor ESR1 mutations. 

ESR1 mutations are present in up to 40 percent of ER-positive and HER2-negative advanced or metastatic breast cancer.

Stemline Therapeutics is a Menarini Group subsidiary. Menarini acquired the rights to elacestrant from Radius Health in July 2020.