capecitabine + cetuximab + irinotecan + oxaliplatin

This is a four-drug combination regimen consisting of capecitabine, cetuximab, irinotecan, and oxaliplatin. It is used primarily in the treatment of metastatic colorectal cancer (mCRC), particularly in patients with RAS or KRAS wild-type tumors. Capecitabine is an oral prodrug of 5-fluorouracil (5-FU) that inhibits thymidylate synthase, interfering with DNA synthesis. Cetuximab is a monoclonal antibody targeting the epidermal growth factor receptor (EGFR), blocking downstream signaling pathways involved in tumor cell proliferation and survival. Irinotecan inhibits topoisomerase I, leading to DNA damage during replication. Oxaliplatin forms platinum-DNA adducts that disrupt DNA replication and transcription. This combination leverages multiple mechanisms to maximize antitumor activity but can be associated with significant toxicity including gastrointestinal side effects, neuropathy, skin reactions, and myelosuppression[1][6][7][8][9].