In women with endocrine-sensitive ER+ BC on adjuvant endocrine therapy (ET) for at least 3 years or who responded to the most recent ET for metastatic disease for at least 6 months, CBR24 was 32% for those treated with enobosarm (9 mg daily), and 29% for those in the 18 mg cohort. Here, ESR1 is linked to breast cancer.