Toripalimab,Celecoxib and Regorafenib in the Treatment of Refractory Advanced Colorectal Cancer

At present, the microsatellite stabilized (MSS) type of advanced refractory metastatic colorectal cancer (mCRC) has a poor median overall survival time of only about 7 months, and there is a significant unmet clinical demand for the efficacy of posterior treatment. Research has found that patients with microsatellite instability (dMMR/MSI-H) type colorectal cancer can achieve long-term survival through immune checkpoint inhibitors (ICIs) treatment, but currently accounting for about 95% of MSS type mCRC, the benefits from immune checkpoint inhibitors are very limited. REGONIVO is a Phase Ib study to explore the efficacy and safety of regorafenib in combination with nivolumab in the treatment of gastric cancer and colorectal cancer with MSS. The study enrolled 50 patients with advanced disease, including 25 cases of gastric cancer, 25 cases of colorectal cancer, except for one case of colorectal cancer with MSI-H, and others were MSS type. The results of the study showed that patients with colorectal cancer had an objective response rate (ORR) of 36%.The ORR of liver matestasis vs. lung matestasis is 8.7% vs. 50%.A phase Ib /Ⅱ clinical study REGOTORI enrolled 39 subjects, with a total ORR of 15.2%, and the ORR of non-liver metastasis subjects compared with liver metastasis subjects was 30% and 8.7% respectively. Based on the prospective small sample clinical trial results of other regifenib combined with PD-1 monoclonal antibody drugs, the overall ORR is between 0% and 33.3%, the ORR for non-liver metastases is between 20% and 50%, and the ORR for liver metastases is between 0% and 15%. In this study, pMMR /MSS type patients with refractory advanced colorectal cancer without liver metastasis were selected as the subjects. Regorafenib, Toripalimab and Celecoxib were used to evaluate the maximum tolerable dose, objective response rate (ORR), total survival time (OS), progression free survival time (PFS), disease control rate (DCR), response duration (DoR) and safety of the subjects.