Node-Sparing Short-Course Radiation Combined With Capecitabine and PD-1/CTLA-4 for MSS Early Rectal Cancer

Sponsor
Sir Run Run Shaw Hospital
Study ID
NCT07068763
Phase
PHASE2
Status
Recruiting
Apply to this trial

Conditions

Eligibility Criteria

Sex
ALL
Age
18 Years - 80 Years
Healthy Volunteers
Not accepted

Interventions

  • Lymph-node-sparing short-course radiotherapy — RADIATION
    Three-dimensional conformal or intensity-modulated radiotherapy targeting only the primary tumor bed (no regional lymph nodes), delivering a total dose of 25 Gy in 5 Gy fractions over five consecutive days.
  • Capecitabine — DRUG
    Oral capecitabine 1,000 mg/m² administered twice daily on Days 1-14 of each 21-day cycle, for a total of four cycles.
  • PD-1/CTLA-4 inhibitor (Aiparolitoworixureli injection) — DRUG
    Intravenous PD-1/CTLA-4 bispecific monoclonal antibody at 5 mg/kg every 3 weeks for four cycles, starting on Day 8 after completion of radiotherapy.

Study Details

This is a single-arm, prospective, multicenter study evaluating a novel neoadjuvant treatment strategy for patients with early, mid-low rectal adenocarcinoma that is microsatellite stable (MSS). Instead of irradiating regional lymph nodes, we deliver short-course radiotherapy (25 Gy in 5 fractions) exclusively to the primary tumor ("lymph-node-sparing" approach), immediately followed by four 3-week cycles of capecitabine plus combined PD-1/CTLA-4 immune checkpoint inhibitors. Two weeks after completing chemo-immunotherapy, tumor response is assessed. Patients who achieve a clinical complete response may enter a "watch-and-wait" program; others will undergo local excision or total mesorectal excision (TME) as appropriate. The primary endpoint is the rate of complete response (clinical and pathological). Secondary endpoints include organ-preservation rate, 3-year local recurrence, 3-year disease-free and overall survival, toxicity, and quality-of-life measures. Results from a pilot study suggest that this regimen may substantially improve complete response rates while reducing radiation-related toxicity, potentially allowing more patients to avoid radical surgery and permanent stoma.

Key Dates

First listed
Jul 16, 2025
Start date
Oct 9, 2025
Status verified
Jan 2026
Primary completion
Dec 31, 2026
Completion
Dec 31, 2029

Study Design

Enrollment
52 participants (estimated)
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT

Arms

  • Experimental: Experimental Arm
    Patients receive lymph-node-sparing short-course radiotherapy of 25 Gy delivered in five daily fractions to the primary tumor bed (no nodal fields). Beginning on treatment Day 8, patients receive capecitabine 1,000 mg/m² orally twice daily on Days 1-14 plus PD-1/CTLA-4 inhibitor (5 mg/kg IV every 3 weeks) for four cycles. Tumor response is assessed 1-2 weeks after the last cycle; patients with clinical complete response enter a watch-and-wait program, while non-responders proceed to local excision or total mesorectal excision.

Primary Outcome Measure

Clinical and pathological complete response rate (CR rate) [ Time Frame: Up to 12 weeks after completion of chemo-immunotherapy ]

Central Contacts

Find similar trials

Nationwide
Colorectal cancer trialsOncology trialsGI oncology trials

Related Studies