Anti-PD-1 Antibody Plus Regorafenib in Refractory Microsatellite Stable Metastatic Colorectal Cancer

The patients were treated orally with regorafenib (80 mg once daily for 21 days on/7 days off, over a 28-day cycle), combined with 1 of the 5 anti-PD-1 antibodies (i.e., nivolumab, pembrolizumab, camrelizumab, sintilimab, or toripalimab). The anti-PD-1 antibody was administered intravenously on day 1, and its recommended dosage was as follows: nivolumab: 240 mg, every 2 weeks; pembrolizumab, camrelizumab, and sintilimab: 200 mg every 3 weeks; and toripalimab: 240 mg every 3 weeks