ESR1 and breast carcinoma: EMBER-3 is an open-label, randomized 3-arm phase 3 study that compared the safety and efficacy of imlunestrant monotherapy vs. SOC ET (exemestane or fulvestrant) vs. imlunestrant plus abemaciclib among advanced ER+ HER2− breast cancer patients who have previously received an ET for advanced breast cancer [68].