NCT06923345

Modified Long-Course Radiotherapy Followed by Chemotherapy and PD-1 Inhibitor for MSS/pMMR High-risk Mid/Low LARC (MODIFI-RC-I)

Modified Long-Course Radiotherapy (Reduced vs. Conventional CTV), Sequential Chemotherapy and PD-1 Inhibitor in Locally Advanced, MSS, Mid-Low Rectal Cancer: An Open-Label, Two-Arm, Randomized, Prospective Phase II Clinical Trial (MODIFI-RC-I)

• Status: Recruiting
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 80 (estimated)
• Sponsor: Sixth Affiliated Hospital, Sun Yat-sen University · Academic / Other
• Sex: All
• Age: 18 Years – 75 Years
• Healthy volunteers: Not accepted

Summary

The goal of this clinical trial is to evaluate whether a total neoadjuvant therapy (TNT) regimen combining long-course chemoradiotherapy, sequential chemotherapy, and PD-1 inhibitor can improve response rates, enhance tolerability, and improve prognosis in patients with locally advanced, microsatellite-stable (MSS) rectal cancer. The main questions it aims to answer are: Does this TNT approach improve complete response (CR) rates? How does selective reduction of clinical target volume (CTV) to S2/S3 level compare with conventional CTV irradiation in terms of efficacy and safety? Researchers will compare a selective CTV reduction group and a conventional CTV irradiation group to assess differences in treatment outcomes, including complete response, tumor regression grading (TRG), organ preservation, R0 resection rates, and long-term survival. Participants will: Receive long-course chemoradiotherapy with either conventional or reduced CTV irradiation. Undergo sequential chemotherapy. Receive PD-1 inhibitor treatment. Be monitored for safety, tumor regression, and long-term survival outcomes.

Conditions

• Rectal Cancer
• Neoadjuvant Therapies
• Immune Checkpoint Therapy
• Radiotherapy

Interventions

Type	Name	Description
COMBINATION_PRODUCT	Reduced CTV	Long-course radiotherapy with selective CTV reduction (lower to S2/S3 level) + CAPOX + PD-1 inhibitor. After treatment, patients will undergo TME surgery or a watch-and-wait approach, depending on response.
COMBINATION_PRODUCT	Conventional CTV	Long-course radiotherapy with conventional CTV irradiation + CAPOX + PD-1 inhibitor. After treatment, patients will undergo TME surgery or a watch-and-wait approach, depending on response.

Timeline

• Start date: 2025-03-31
• Primary completion: 2027-12-31
• Completion: 2028-12-31
• First posted: 2025-04-11
• Last updated: 2025-04-18

Locations

1 site across 1 country: China