Imlunestrant with or without abemaciclib in advanced breast cancer: Updated efficacy results from the phase III EMBER-3 trial

The EMBER-3 trial evaluated imlunestrant alone versus standard of care (SOC) and versus imlunestrant plus abemaciclib in previously treated patients with ER+ HER2- advanced breast cancer. In patients with ESR1 mutations, imlunestrant demonstrated sustained progression-free survival (PFS) benefit and a numerically longer median overall survival (OS) versus SOC. In all patients, the addition of abemaciclib extended PFS to 10.9 months and delayed time to chemotherapy, although OS data remain immature.