Antibody-Drug Conjugates for Breast Cancer — Year in Review Series on Relevant New Datasets and Advances

Antibody-drug conjugates (ADCs) are transforming the treatment landscape for metastatic breast cancer across HER2-positive, triple-negative, and hormone receptor-positive subtypes. Trastuzumab deruxtecan (TDXD) has established high efficacy in HER2-positive disease, prompting discussions on transitioning to maintenance therapies to mitigate toxicities like interstitial lung disease. In triple-negative breast cancer, TROP2-directed agents such as sacituzumab govitecan and datopotamab deruxtecan provide viable alternatives to traditional chemotherapy, especially for patients ineligible for immunotherapy. Clinical decision-making now emphasizes managing specific side effects, including ocular toxicity and mucositis, through prophylactic measures like steroid mouthwashes. As these agents move into earlier neoadjuvant settings, clinicians must navigate complex sequencing strategies and individualize care based on patient response, biomarker profiles, and the risk of cumulative toxicities.