CAPOX and Bevacizumab With or Without Primary Tumor Radiotherapy and Iparomlimab and Tuvonralimab as First-line Treatment for RAS-Mutant/MSS Metastatic Rectal Cancer

Conditions

• Rectal Neoplasms Malignant

Eligibility Criteria

Sex

ALL

Age

18 Years - 75 Years

Healthy Volunteers

Not accepted

Interventions

• Iparomlimab and Tuvonralimab — DRUG
  (Experimental group) PD-1/CTLA-4 Antibody
• Radiotherapy to the primary site — RADIATION
  (Experimental group) Radiotherapy to the primary site of rectal
• Capecitabine — DRUG
  (both groups)
• Bevacizumab — DRUG
  (both groups)
• Oxaliplatin injection — DRUG
  (both groups)

Study Details

Research objective: To compare the efficacy and safety of Capox + Bev versus Capox + Bev combined with primary site radiotherapy + (Iparomlimab and Tuvonralimab) as the first-line treatment for RAS Mutation/pMMR metastatic rectal cancer patients. Study endpoint: Primary endpoint: 12-month progression-free survival rate (PFSR) Secondary endpoints: * The objective response rate (ORR) and disease control rate (DCR) as determined by the investigator according to the RECIST 1.1 standard, time to response (TTR), duration of response (DOR), progression-free survival (PFS), 6-month progression-free survival rate (PFSR), overall survival (OS); * The frequency and severity of adverse events (AEs) during treatment (NCI CTCAE 5.0). This study will enroll 106 patients (stratification factors: presence or absence of liver metastasis; whether NED could be achieved). They were randomly assigned in a 1:1 ratio to: The treatment group: Capox + Bev combined with primary site radiotherapy and (Iparomlimab and Tuvonralimab), administered every 3 weeks (Q3w), up to a maximum of 8 cycles, followed by a maintenance treatment stage of Capecitabine + Bev + (Iparomlimab and Tuvonralimab), administered every 3 weeks (Q3w). The control group: Capox + Bev, administered every 3 weeks (Q3w), up to a maximum of 8 cycles, followed by a maintenance treatment stage of Capecitabine + Bev, administered every 3 weeks (Q3w).

Key Dates

First listed

Feb 3, 2026

Start date

Feb 1, 2026

Status verified

Jan 2026

Primary completion

Dec 31, 2029

Completion

Dec 31, 2029

Study Design

Enrollment

106 participants (estimated)

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Arms

• Experimental: Experimental group
  Experimental group: Capox + Bev combined with primary lesion radiotherapy and (Iparomlimab and Tuvonralimab), administered once every 3 weeks (Q3w), for a maximum of 8 cycles. Then, it entered the maintenance treatment stage with Capecitabine + Bev + (Iparomlimab and Tuvonralimab), administered once every 3 weeks (Q3w).
• Active Comparator: Control group
  Control group: Capox + Bev, administered once every 3 weeks (Q3w), for a maximum of 8 cycles. Then, it entered the maintenance treatment stage with Capecitabine + Bev, administered once every 3 weeks (Q3w).

Primary Outcome Measure

12-month disease-free survival rate (progression-free survival rate, PFSR) [ Time Frame: From randomization to disease progression or death from any cause, whichever occurs first; the progression-free survival rate will be estimated at 12 months. ]