Interstitial pneumonitis related to trastuzumab deruxtecan, a human epidermal growth factor receptor 2‐targeting Ab–drug conjugate, in monkeys

Trastuzumab deruxtecan (T‐DXd: DS‐8201a) is an anti‐human epidermal growth factor receptor 2 (HER2) Ab–drug conjugated with deruxtecan (DXd), a derivative of exatecan. The objective of this study was to characterize T‐DXd‐induced lung toxicity in cynomolgus monkeys. Trastuzumab deruxtecan was injected i.v. into monkeys once every 3 weeks for 6 weeks (10, 30, and 78.8 mg/kg) or for 3 months (3, 10, and 30 mg/kg). To evaluate the involvement of...