A Phase ll Study of Neoadjuvant Short-course Radiotherapy Followed by Ivonescimab and Chemotherapy in pMMR/MSS Locally Advanced Rectal Cancer

The purpose of this study is to evaluate the efficacy and safety of short-course radiotherapy followed by ivonescimab and chemotherapy in participants with pMMR/MSS locally advanced rectal cancer. Patients were randomly assigned to experimental group A or control group B according to a 1:1 ratio. In group A, patients will receive neoadjuvant short-course radiotherapy followed by ivonescimab and chemotherapy. In group B, patients will receive neoadjuvant short-course radiotherapy followed by chemotherapy. After neoadjuvant treatment, the patients and investigator could choose one of the following treatments:(1) Surgery. The patients will receive surgery within 4-8 weeks after the last dose of capecitabine, and the surgical method is selected by the investigator, (2) Watch and Wait (only for patients with clinical complete response after neoadjuvant therapy).

NCT Number	NCT06919510
Lead Sponsor	Sun Yat-sen University Collaborators: Akeso
Conditions	Rectal Adenocarcinoma
Enrollment	90 participants
Start Date	2025-04-01
Primary Completion	2026-06-01 (estimated)
Study Completion	2028-12-01 (estimated)
Updated on ClinicalTrials.gov	2025-04-09