erlotinib + bevacizumab + 5-fluorouracil + leucovorin + irinotecan

This is a **multi-agent combination chemotherapy regimen** consisting of five drugs: erlotinib, bevacizumab, 5-fluorouracil, leucovorin, and irinotecan. Erlotinib is a small molecule inhibitor of the epidermal growth factor receptor (EGFR) tyrosine kinase, primarily used in EGFR-mutant non–small cell lung cancer (NSCLC). Bevacizumab is a monoclonal antibody targeting vascular endothelial growth factor (VEGF), inhibiting tumor angiogenesis. 5-Fluorouracil is a pyrimidine analog that inhibits thymidylate synthase, disrupting DNA synthesis. Leucovorin enhances the cytotoxicity of 5-fluorouracil by stabilizing its binding to thymidylate synthase. Irinotecan is a topoisomerase I inhibitor that prevents DNA replication, leading to cell death. These agents are frequently combined in clinical oncology for synergistic antineoplastic effects targeting both cell proliferation and tumor vasculature in various solid tumors, especially advanced colorectal cancer and sometimes lung cancer, although the five-drug combination is less common than subsets thereof[1][2][3][4].