robatumumab + irinotecan + folinic acid + 5-fluorouracil

This is a **combination chemotherapy regimen** composed of robatumumab (a monoclonal antibody targeting IGF-1 receptor), irinotecan (a topoisomerase I inhibitor), folinic acid (leucovorin, a folate analog), and 5-fluorouracil (a pyrimidine analog antimetabolite). Robatumumab binds and inhibits the insulin-like growth factor 1 receptor (IGF-1R), reducing tumor cell proliferation. Irinotecan inhibits topoisomerase I, disrupting DNA replication. 5-fluorouracil inhibits thymidylate synthase and incorporates into RNA/DNA, resulting in defective DNA synthesis and function. Folinic acid enhances binding of 5-fluorouracil to thymidylate synthase, increasing cytotoxicity[2][4]. This regimen is primarily investigated for advanced colorectal cancer and other digestive tract tumors as part of synergistic, multi-targeted cytotoxic therapy[3][4].