The main purpose of this study is to measure how well imlunestrant works compared to standard hormone therapy in participants with early breast cancer that is estrogen receptor positive (ER+) and human epidermal receptor 2 negative (HER2-). Participants must have already taken endocrine therapy for two to five years and must have a higher-than-average risk for their cancer to return. Study participation could last up to 10 years.
EMBER-4: A Randomized, Open-Label, Phase 3 Study of Adjuvant Imlunestrant vs Standard Adjuvant Endocrine Therapy in Patients Who Have Previously Received 2 to 5 Years of Adjuvant Endocrine Therapy for ER+, HER2- Early Breast Cancer With an Increased Risk of Recurrence