SCRT Followed by AK112 in pMMR/MSS Mid-low Rectal Cancer

Primary Objectives： Evaluate the complete response rate (CR rate) and safety of short - course radiotherapy combined with ivonesimab (AK112) in patients with pMMR/MSS mid - low rectal cancer. Secondary Objectives： Evaluate treatment - related toxic reactions, the quality of life, long - term prognosis (local control \[LC\], disease - free survival \[DFS\] and overall survival \[OS\]). Patients will : Receive Radiotherapy: Pelvic IMRT or VMAT, DT 25Gy/5Fx. One week after radiotherapy, begin treatment with Ivorsimab (AK112) at a dose of 20mg/kg by intravenous drip on day 1. One cycle is 21 days, and a total of 6 cycles are to be carried out. Evaluate the curative effect after 3 cycles of treatment. Patients with progressive disease (PD) will withdraw from the study, and other treatment plans will be adjusted in a timely manner. Patients with CR/PR/SD will continue treatment for another 3 cycles. Conduct a comprehensive assessment after 6 cycles of treatment. Patients who achieve cCR can choose the watch - and - wait approach. For patients who do not achieve cCR, TME surgery is recommended. Decide whether to perform adjuvant chemotherapy based on the postoperative pathological findings.

NCT Number	NCT07162714
Lead Sponsor	Zhejiang Cancer Hospital Collaborators: Akeso
Conditions	Rectal Cancer, Radiation, AK112
Enrollment	30 participants
Start Date	2025-10-27
Primary Completion	2027-03-31 (estimated)
Study Completion	2028-12-31 (estimated)
Updated on ClinicalTrials.gov	2026-08-07