Phase I Study of Biweekly SIRB Regimen for Metastatic Colorectal Cancer

In several clinical studies from Japan and South Korea, the combination regimen of S-1 and irinotecan has shown efficacy in the treatment of advanced colorectal cancer, and a Phase III study（TRICOLORE） showed that the combination therapy with S-1/irinotecan/bevacizumab (a 3-week regimen \[SIRB\] or 4-week regimen \[IRIS/bevacizumab\]) is not inferior to the oxaliplatin-based standard treatment (mFOLFOX6/bevacizumab or CapeOX/bevacizumab) in patients with metastatic colorectal cancer who had not previously received chemotherapy. Here, we design this phase I study to explore the Chinese population's tolerability and efficacy of Biweekly SIRB Regimen(S-1/irinotecan/bevacizumab) and to explore the recommended dose of irinotecan in this regimen.