ASCO 2022 | DESTINY-Breast03: safety follow-up results

Erika Hamilton, MD, Sarah Cannon Research Institute, Nashville, TN, discusses updated safety follow-up results from DESTINY-Breast03 (NCT03529110), a Phase III study evaluating trastuzumab deruxtecan (T-DXd) versus trastuzumab emtansine (T-DM1) in patients with HER2-positive, unresectable and/or metastatic breast cancer. In this updated safety analysis, T-DXd demonstrated a tolerable safety profile consistent with prior studies. Despite longer treatment duration with T-DXd, exposure-adjusted incidence rates of grade ≥3 and serious adverse events were lower for T-DXd vs T-DM1. Rates of interstitial lung disease/pneumonitis for T-DXd were similar to those in the previous data cut-off. Nausea, vomiting, and alopecia rates decreased over time. This longer safety update reinforces the consistent safety profile of T-DXd, supporting the clinical benefit of T-DXd over T-DM1 in patients with HER2+ mBC. This interview took place at the American Society of Clinical Oncology (ASCO) 2022 Annual Meeting in Chicago, IL.