Cetuximab Re-challenge for Colorectal Cancer Liver Metastasis

Inclusion Criteria: 1. Primary tumour was histologically confirmed colorectal adenocarcinoma; 2. Clinical or radiological evidence of non-resectable liver metastases; 3. With at least one measurable tumor; 4. Received first-line cetuximab (RAS gene wild type) treatment and progressed 5. Received second-line non-cetuximab treatment and progressed 6. Received circulating tumor DNA test and has RAS gene wild type status; 7. Performance status (ECOG) 0\~1 8. A life expectancy of ≥ 3 months 9. Adequate hematological function: Neutrophils≥1.5 x109/l and platelet count≥100 x109/l; Hb ≥9g/dl (within 1 week prior to randomization) 10. Adequate hepatic and renal function: Serum bilirubin≤1.5 x upper limit of normal (ULN), alkaline phosphatase ≤5x ULN, and serum transaminase (either aspartate transaminase (AST) or alanine transaminase (ALT)) ≤ 5 x ULN(within 1 week prior to randomization); 11. Written informed consent for participation in the trial. Exclusion Criteria: 1. Patients with known hypersensitivity reactions to any of the components of the study treatments. 2. Acute or sub-acute intestinal occlusion 3. Pregnancy (absence confirmed by serum/urine β-HCG) or breast-feeding 4. Other previous malignancy within 5 years, with exception of a history of a previous basal cell carcinoma of the skin or pre-invasive carcinoma of the cervix Known drug abuse/ alcohol abuse 5. Legal incapacity or limited legal capacity 6. Pre-existing peripheral neuropathy.