A multicenter Phase II study of mFOLFOX6 plus nivolumab for gastric cancer with severe peritoneal metastases: WJOG16322G.

Advanced gastric cancer (AGC) patients with severe peritoneal metastases (SPM), characterized by massive ascites and/or inadequate oral intake, have a poor prognosis with the median overall survival of around 7 months, even when treated with fluorouracil/l-leucovorin plus oxaliplatin (mFOLFOX6), despite being a treatment options for these patients demonstrated in the WJOG10517G study. However, these patients were excluded from pivotal Phase III trials, including the CheckMate 649 study, which demonstrated the benefit of adding nivolumab to mFOLFOX6, due to tumor-related complications. Given the lack of data on the efficacy and safety of combining nivolumab with mFOLFOX6 for AGC patients with SPM, we initiated a Phase II study to evaluate this combination. The primary endpoint was the 1-year survival rate. Japan Registry of Clinical Trials (jRCTs) 041220164.