Antitumor Activity and Safety of Trastuzumab Deruxtecan in Patients With HER2-Low–Expressing Advanced Breast Cancer: Results From a Phase Ib Study

The novel HER2-targeted ADC, T-DXd, demonstrated promising preliminary antitumor activity in patients with HER2-low breast cancer. Most toxicities were GI or hematologic in nature. ILD is an important identified risk and should be monitored closely and proactively managed.