ERBB2 and breast cancer: A new generation of ADCs, fam-trastuzumab deruxtecan-nxki (T-DXd), which combines trastuzumab with the topoisomerase inhibitor MAAA-1181a, dramatically improved ORR, DFS, and overall survival in HER2-positive metastatic breast cancer patients, demonstrated superior efficacy than T-DM1, and received accelerated FDA approval for treating HER2-positive breast cancer patients who have received two or more prior HER2-targeted regimens [44].