Phase II Trial of CAPOX and PD-1 Antibody With or Without Radiotherapy for Microsatellite Stable Locally Advanced Rectal Cancer

What this Trial Is About

Researchers are evaluating treatments for patients with locally advanced rectal cancer LARC to compare total neoadjuvant therapy TNT approaches. This prospective, randomized phase II trial involves 198 patients with specific stages of rectal cancer who have tumors located close to the anal verge and no distant metastases. The study aims to assess the complete response rate, including both pathological and clinical complete responses, and also tracks safety and organ preservation outcomes over three years. Participants are assigned to one of two groups. Group A receives six cycles of Toripalimab, a PD-1 inhibitor, combined with chemotherapy drugs capecitabine and oxaliplatin called ToriCAPOX. Group B receives short-course radiotherapy followed by the same six cycles of ToriCAPOX. After TNT, total mesorectal excision TME surgery is planned, but a watch and wait approach may be used if a clinical complete response is achieved. During the study, patients will be monitored for treatment response, side effects, and organ preservation rates. Researchers will perform follow-ups for up to three years to evaluate disease-free survival, local recurrence, distant metastasis, overall survival, and surgical complications. The main outcome is the complete response rate measured about one month after surgery or the decision for watch and wait, with safety monitored through adverse effect rates up to three months after therapy.

CAPOX and PD-1 Antibody Combined With or Without Radiotherapy for MSS Locally Advanced Rectal Cancer