This is a Phase 2 trial evaluating the efficacy of elacestrant in patients with estrogen receptor positive (ER+)/human epidermal growth factor receptor-2 negative (HER2-) advanced/metastatic breast cancer who received one or two prior hormonal therapies and no prior cyclin-dependent kinase targeting enzymes CDK4 and CDK6 inhibitor (CDK4/6i) in the metastatic setting.~The study duration for each patient is estimated to be:~Screening Phase: Up to 21 days prior to Cycle 1, Day 1 (C1/D1);~Treatment Phase: From C1/D1 until the date of radiologically documented progression, or treatment discontinuation due to other reasons.~Survival Follow-Up Phase: All patients will be followed for survival approximately every 3 months up to 24 months after enrollment of the last patient.~Patients will be followed for AEs for 28 days after the last treatment administration.
The purpose of this study is to evaluate the efficacy and safety of elacestrant over the course of 6 months in patients with ER+/HER2- advanced/metastatic breast cancer who received no prior CDK4/6i in the metastatic setting.