Management of toxicities from antibody - drug conjugates in breast cancer.

Background: Antibody-drug conjugates (ADCs) have transformed breast-cancer therapeutics by combining targeted antibody delivery with potent cytotoxic payloads. With the expanding use of trastuzumab deruxtecan (T-DXd), sacituzumab govitecan (SG), and datopotamab deruxtecan (Dato-DXd) across HER2-positive, HER2-low, and hormone-receptor-positive disease, management of treatment-related toxicities has become a critical determinant of outcomes. Objective: To synthesize clinical-trial, post-marketing, and real-world data to create a unified, organ-system-based framework for anticipating, preventing, and managing toxicities associated with these ADCs. Methods: A targeted narrative review was conducted using PubMed, Embase, and ClinicalTrials.gov (January 2019 - December 2025). Phase II/III trials, meta-analyses, pharmacovigilance studies, and expert-consensus guidelines on ADC safety in breast cancer were included. Pre-clinical and non-breast ADC studies were excluded. Results: Comparative synthesis demonstrates overlapping but distinct toxicity signatures driven by payload, linker stability, and antigen expression. Integrating these findings, we propose practical algorithms for managing pulmonary, gastrointestinal, hematologic, ocular, and mucosal adverse events. Conclusion: This review consolidates evidence into a clinician-oriented reference for ADC toxicity management, emphasizing multidisciplinary coordination, early recognition, and system-specific mitigation strategies to enhance treatment safety and adherence.