capecitabine + fluorouracil + leucovorin + liposomal irinotecan + oxaliplatin

This is a five-drug combination regimen consisting of capecitabine, fluorouracil, leucovorin, liposomal irinotecan, and oxaliplatin. Each component is a cytotoxic or modulating agent used in the treatment of advanced gastrointestinal cancers. Capecitabine is an oral prodrug of 5-fluorouracil (5-FU), which inhibits thymidylate synthase and disrupts DNA synthesis. Fluorouracil (5-FU) is a pyrimidine analog that also inhibits thymidylate synthase, leading to impaired DNA replication and cell death. Leucovorin enhances the binding of 5-FU to its target enzyme, increasing its efficacy. Liposomal irinotecan (nal-IRI) is a topoisomerase I inhibitor encapsulated in liposomes for improved delivery and reduced toxicity; it prevents DNA re-ligation during replication, causing double-strand breaks and apoptosis. Oxaliplatin forms platinum-DNA adducts that inhibit DNA synthesis and transcription. While combinations such as FOLFOX (fluorouracil/leucovorin/oxaliplatin), FOLFIRI (fluorouracil/leucovorin/irinotecan), XELOX/XELIRI (capecitabine with oxaliplatin or irinotecan), and NALIRIFOX (liposomal irinotecan/oxaliplatin/fluorouracil/leucovorin) are established regimens for colorectal or pancreatic cancer[1][2][4][7][8], there are no published studies or regulatory approvals specifically describing the use of all five agents together in one regimen as listed here.