Short-Course Radiotherapy Followed by CAPOX With or Without Iparomlimab and Tuvonralimab in pMMR/MSS Locally Advanced Rectal Cancer

NCT07686640 · tracked via the Priya Life Science China tracker

Sponsor

Shandong Cancer Hospital and Institute

Phase

Phase 3

Started

2026-08-15

Last updated

2026-08-18

Condition(s) studied

Local Advanced Rectal CancerRadiotherapyImmunotherapy

Investigational drug(s) / intervention(s)

Short-Course RadiotherapyConsolidation treatment (With ICIs)Consolidation treatment (Without ICIs)

Short-Course Radiotherapy: Short-course external-beam radiotherapy will be delivered to the rectal primary tumor and corresponding lymphatic drainage regions using IMRT or VMAT. The prescribed dose is 25 Gy in 5 fractions over 1 week. No concurrent chemotherapy will be administered during short-course radiotherapy.

Consolidation treatment (With ICIs): Iparomlimab and tuvonralimab injection will be administered at 5 mg/kg by intravenous infusion every 21 days for 6 cycles. CAPOX chemotherapy will consist of oxaliplatin 130 mg/m² intravenously on day 1 plus capecitabine 1000 mg/m² orally twice daily on days 1-14 of each 21-day cycle, for 6 cycles.

Consolidation treatment (Without ICIs): CAPOX chemotherapy will consist of oxaliplatin 130 mg/m² intravenously on day 1 plus capecitabine 1000 mg/m² orally twice daily on days 1-14 of each 21-day cycle, for 6 cycles.

Study summary

This multicenter, randomized, controlled, phase III trial evaluates whether adding iparomlimab and tuvonralimab injection to CAPOX consolidation chemotherapy after short-course radiotherapy improves tumor response in patients with treatment-naive, proficient mismatch repair/microsatellite-stable (pMMR/MSS) locally advanced rectal adenocarcinoma. Eligible patients will be randomly assigned in a 1:1 ratio to receive short-course radiotherapy followed by CAPOX plus iparomlimab and tuvonralimab, or short-course radiotherapy followed by CAPOX alone.

After total neoadjuvant therapy, patients with a clinical complete response may undergo a Watch-and-Wait strategy, whereas other patients will undergo total mesorectal excision according to standard clinical practice. The primary endpoint is complete response rate, defined as pathologic complete response after surgery or clinical complete response sustained for more than 1 year. Secondary endpoints include 3-year relapse-free survival, 3-year overall survival, sphincter preservation rate, and grade 3-4 acute adverse events. Exploratory analyses will assess tissue and blood biomarkers associated with treatment response.

Eligibility

Sex

ALL

Min age

18 Years

Max age

75 Years

Healthy volunteers

Inclusion Criteria: * Patients aged 18-75 years with histologically confirmed pMMR/MSS rectal adenocarcinoma are eligible if they have MRI-defined clinical stage II or III disease according to AJCC 8th edition, tumor located within 12 cm from the anal verge, and at least one high-risk feature, including cT4b, cN2, EMVI positivity, MRF positivity, lateral lymph node positivity, tumor deposits, or tumor located ≤5 cm from the anal verge. Patients must have no distant metastasis, ECOG performance status 0-1, life expectancy greater than 6 months, and adequate hematologic, hepatic, and renal function Exclusion Criteria: * active or prior autoimmune disease requiring systemic treatment, use of immunosuppressive therapy or systemic corticosteroids at immunosuppressive doses, severe hypersensitivity to monoclonal antibodies, uncontrolled cardiac disease, significant coagulopathy or bleeding tendency, active infection, interstitial lung disease or severe pulmonary dysfunction, HIV infection or active hepatitis, prior or concurrent malignancy except specified cured cancers, recent investigational drug use, planned use of other systemic antitumor therapy during the study, pregnancy or breastfeeding, and any other condition judged by the investigator to make participation unsuitable.

Primary outcome measure(s)

Complete Response (CR) Rate — From randomization to completion of definitive response assessment, including surgical pathological assessment after total neoadjuvant therapy or confirmation of sustained clinical complete response after at least 12 months of Watch-and-Wait follow-up
Complete response rate is defined as the proportion of patients who achieve either pathologic complete response (pCR) after surgery or sustained clinical complete response (cCR) for more than 1 year during Watch-and-Wait follow-up.

Trial sites (1)

Facility	City	Region	Status
Shandong Cancer Hospital and Institute	Jinan	Shandong	Recruiting

Official registry record

This page summarises publicly available registry data for informational purposes — not medical advice. Eligibility is determined by each study team; patients should discuss participation with their clinician.

View NCT07686640 on ClinicalTrials.gov ↗ ← All trials in China