Negative Ultraselection of Patients With RAS/BRAF Wild-type Refractory Right-Sided Metastatic Colorectal Cancer Receiving Cetuximab in Combination With Toripalimab and Irinotecan: A Phase II, Single-arm Study
The objective of this clinical trial is to evaluate the efficacy and safety of cetuximab combined with PD-1 inhibitor and irinotecan in negative ultraselection RAS/BRAF wild-type refractory right-sided metastatic colorectal cancer.
• Histologically confirmed colorectal adenocarcinoma.
• Primary tumor located in the right colon.
• Metastatic disease with at least one measurable lesion according to RECIST v1.1 criteria.
• Histologically tested as RAS/BRAF V600E wild-type and negative ultraselected for mutations including: RAS/BRAF V600E/PIK3CA/PTEN/EGFR (ECD), HER2 and MET amplification, and ALK/RET/NTRK1 gene fusions.
• Patients who have progressed after previous treatments including bevacizumab, irinotecan, oxaliplatin, and 5-fluorouracil, with tumor progression occurring during or within 3 months after irinotecan treatment.
• No prior treatment with anti-EGFR or PD-1 antibodies.
• Normal hematological function (platelets \>90×10\^9/L; white blood cells \>3×10\^9/L; neutrophils \>1.5×10\^9/L).
• Serum bilirubin ≤1.5 times the upper limit of normal (ULN), transaminases ≤5 times ULN.
• No ascites, normal coagulation function, albumin ≥35 g/L.
• Liver function classified as Child-Pugh grade A.
• Serum creatinine less than ULN, or calculated creatinine clearance \>50 ml/min (using the Cockcroft-Gault formula).
• At least one measurable lesion according to RECIST v1.1 criteria.
• ECOG performance status of 0-2.
• Expected survival \>3 months.
• Signed written informed consent.
• Willing and able to undergo follow-up until death or study completion or termination.