Clinical Practices and Institutional Protocols on Prophylaxis, Monitoring, and Management of Selected Adverse Events...

The treatment of metastatic breast cancer (mBC) has evolved significantly in the past several years with the approval of new targeted agents. Trastuzumab deruxtecan (T-DXd), an antibody-drug conjugate with a topoisomerase I inhibitor payload, is a new addition to the class of therapies that target the human epidermal growth factor 2 (HER2) receptor. T-DXd was approved in the US in December 2019 for patients with HER2-positive metastatic or unresectable breast cancer who have received 2 or more prior anti-HER2-based regimens in the metastatic setting. In the DESTINY-Breast01 phase II trial (NCT03248492), T-DXd demonstrated high rates of durable responses in heavily pretreated patients with HER2-positive mBC, with a confirmed objective response rate of 62%, median duration of response of 18.2 months, and median progression-free survival of 19.4 months. In addition to efficacy, successful implementation of any new anticancer therapy includes learning how to prevent, monitor, and manage treatment-related adverse events. As T-DXd becomes more widely used, information can be gained from real-world clinical practices, institutional approaches, and the collaboration of multidisciplinary oncology teams who treat patients with T-DXd. This article reviews practical insights and management of nausea and vomiting, neutropenia, interstitial lung disease, risk of cardiotoxicity, and other adverse events associated with T-DXd administration from the perspective of health care providers who have experience utilizing T-DXd.