Serplulimab Combined With CAPEOX + Celecoxib as Neoadjuvant Treatment for Locally Advanced Rectal Cancer

Colorectal cancer of Mismatch Repair-proficient (pMMR)/ Microsatellite Stability (MSS) accounts for approximately 85% of all colorectal cancer patients, which might be insensitive to immunotherapy. Immunotherapy with monoclonal antibodies, such as pembrolizumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Chemotherapy, such as CAPEOX regimen, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Celecoxib, a COX-2 inhibitor, can improve the immune microenvironment and have a potential to synergy with immunotherapy. Chemotherapy can improve the immunogenicity of cancer cells that might enhance the efficacy of immunotherapy. The aim of this study is to explore whether chemotherapy and cyclooxygenase (COX) inhibitors combined with anti-PD-1 monoclonal antibody (mAb) could improve efficacy for resectable colorectal cancer patient with the pMMR/MSS phenotype.