A randomized, double-blind, placebo-controlled phase II study of olanzapine-based prophylactic antiemetic therapy for delayed and persistent nausea and vomiting in patients with HER2-positive or HER2-low breast cancer treated with trastuzumab deruxtecan: ERICA study (WJOG14320B)

Olanzapine 5 mg for 6 days with 5-hydroxytryptamine type 3 receptor antagonist and dexamethasone appears effective for T-DXd-treated patients to prevent delayed and persistent nausea and vomiting.