5-fluorouracil + folinic acid + ifosfamide

This is a combination chemotherapy regimen consisting of three drugs: - **5-fluorouracil (5FU)** is a pyrimidine analog antimetabolite that inhibits thymidylate synthase, thereby interfering with DNA synthesis and inhibiting cancer cell proliferation[3]. - **Folinic acid (leucovorin or calcium folinate)** enhances the binding of 5-fluorouracil to thymidylate synthase, increasing its cytotoxic effect. Folinic acid itself is not a chemotherapeutic agent but acts as a biomodulator to potentiate the efficacy of 5FU[1][6]. - **Ifosfamide** is an alkylating agent that crosslinks DNA strands, leading to inhibition of DNA replication and cell death. It also has immunosuppressive properties[7]. The combination has been studied in advanced cancers such as metastatic urothelial carcinoma after failure of platinum-based regimens. In clinical trials (e.g., the "FIFO" regimen), this combination showed moderate toxicity but limited efficacy in refractory urothelial cancer patients[2]. The primary mechanism involves synergistic cytotoxicity through disruption of DNA synthesis and direct alkylation-induced damage.

Brand names

FIFO

Other names

fluorouracil + folinic acid + ifosfamide5FU + FA + ifosfamideFIFO regimen