[Current Status and Issue of Emesis and Vomiting Caused by Trastuzumab Deruxtecan]

Emesis and vomiting are the most common adverse events related to trastuzumab deruxtecan(T-DXd). T-DXd is listed as a moderate emetogenic chemotherapy(MEC)agent in the latest guidelines for the appropriate use of antiemetic drugs in Japan; however, the National Comprehensive Cancer Network Guidelines regard it as a highly emetogenic chemotherapy (HEC)agent. We investigated the risk factors for chemotherapy-induced nausea and vomiting(CINV)associated with T-DXd by analyzing data from 40 patients with advanced breast cancer(median age, 56 years)were receiving T-DXd administration between June 2020 and July 2023. CINV was graded using CTCAE v5.0. All patients were treated with antiemetic therapy consisting of a 5-HT3 receptor antagonist(5-HT3RA)and dexamethasone(DEX); 3 patients also received an NK1 receptor antagonist(NK1RA). Emesis was observed in 23(57.5%)(Grade≥2 in 7), and vomiting in 2 patients(5.0%, Grade 1). Emesis occurred >1 day after T-DXd administration in 78.3% and lasted for ≥7 days in 69.6%. These symptoms may be characteristic of T-DXd-related CINV. Antiemetic therapy for CINV in HEC may be considered to control T-DXd-associated CINV in patients aged<50 years or in those who did not achieve sufficient curative effects with MEC.