suizenji + nal-IRI + 5-fluorouracil + leucovorin

This is a **four-drug combination regimen** consisting of Suizenji (a name that may refer to a specific investigational or regional agent, but no definitive identification could be found), **liposomal irinotecan** (nal-IRI), **5-fluorouracil**, and **leucovorin**. The combination is used in oncology, most notably in the treatment of gastrointestinal cancers; liposomal irinotecan is a topoisomerase I inhibitor, 5-fluorouracil is a pyrimidine analog antimetabolite, and leucovorin acts to potentiate the cytotoxic effects of 5-fluorouracil by stabilizing its binding to thymidylate synthase. Liposomal irinotecan, known as nal-IRI, improves drug delivery and pharmacokinetics compared to conventional irinotecan. This regimen is frequently studied or used in advanced gastrointestinal malignancies, particularly pancreatic cancer that has progressed after gemcitabine-based therapy.