Final overall survival (OS) for abemaciclib plus trastuzumab +/- fulvestrant versus trastuzumab plus chemotherapy in patients with HR+, HER2+ advanced breast cancer (monarcHER): A randomized, open-label, phase II trial
Last Updated: Friday, July 17, 2026
Data from the phase 2 monarcHER trial—presented during the 2022 ESMO Congress—show that abemaciclib plus trastuzumab with or without fulvestrant improved median overall survival, compared with chemotherapy plus trastuzumab, in patients with HR+, HER2+ advanced breast cancer.