Study protocol for J-SUPPORT 1604 (J-FORCE): a randomized, double blind, placebo-controlled Phase III study evaluating olanzapine (5 mg) plus standard triple antiemetic therapy for prevention of chemotherapy induced nausea and vomiting in patients receiving cisplatin-based highly emetogenic chemotherapy.

The Guidelines of the Japan Society of Clinical Oncology recommend standard triple antiemetic therapy with aprepitant, a 5-hydroxytryptamine type 3 receptor antagonist and dexamethasone for patients receiving highly emetogenic chemotherapy. Recently, a Phase III study demonstrated the significance of adding of olanzapine (10 mg) to standard triple antiemetic therapy. Olanzapine is associated with somnolence, and we have previously conducted a randomized Phase II study to evaluate the efficacy and safety of 10 mg and 5 mg olanzapine. Lower dose of olanzapine reduced the incidence of somnolence. Therefore, we conducted a randomized, double blind, placebo-controlled, Phase III study to evaluate the efficacy of olanzapine (5 mg) combined with standard triple antiemetic therapy for cisplatin-based highly emetogenic chemotherapy. This study initiated in Feb 2017. A total of 690 patients are planned to be enrolled over a period of 2 years. This study has been registered at the UMIN Clinical Trials Registry as UMIN000024676.