236P Subgroup analysis by disease history and prior treatments of patients (pts) with HER2-positive (HER2+) metastatic breast cancer (MBC) from DESTINY-Breast03, a randomized phase III study of trastuzumab deruxtecan (T-DXd) vs trastuzumab emtansine (T-DM1)

T-DXd showed superior progression-free survival (PFS) vs T-DM1 (HR, 0.28; 95% CI, 0.22-0.37), with manageable safety, in pts with HER2+ MBC in DESTINY-Breast03 (NCT03529110; Cortes 2022). We present additional patient subgroups by disease history and prior treatment.