Sintilimab (IBI308) Combined With Bevacizumab + XELOX Regimen in Metastatic Colorectal Cancer

This study is a phase II clinical study of Sintilimab (IBI308) combined with bevacizumab + XELOX regimen as first-line treatment in patients with RAS-mutant and microsatellite stable metastatic colorectal cancer. The study treatment took 21 days as a treatment cycle. Sintilimab (IBI308), bevacizumab and oxaliplatin were given intravenously on the first day of each cycle, and capecitabine was given from the first day to the 14th day. All adverse events will be graded according to NCI CTCAE (version 5.0). Up to 8 courses of inductive therapy would be given. During the treatment, CT was rechecked every 2 courses to evaluate the curative effect. Patients with objective response or stable disease (SD) would continue to receive sintilimab plus bevacizumab and oral capecitabine in each 21-day cycle as maintenance therapy until the confirmation of disease progression, death, unacceptable toxicity, or withdrawal of consent. A total of 25 patients are planned to be enrolled. When the number of subjects reaches 25 respectively, the enrollment ends to inquire about the safety and efficacy of Sintilimab (IBI308) combined with bevacizumab + XELOX.