fluorouracil + levofolinic acid + mitoxantrone + raltitrexed

This is a four-drug chemotherapy combination consisting of fluorouracil (5-FU), levofolinic acid (calcium levofolinate), mitoxantrone, and raltitrexed. Each component has a distinct mechanism of action: - Fluorouracil is an antimetabolite that inhibits thymidylate synthase, disrupting DNA synthesis and function. - Levofolinic acid enhances the binding of 5-FU to thymidylate synthase, increasing its cytotoxicity; it is not itself cytotoxic but acts as a biomodulator. - Mitoxantrone is an anthracenedione antineoplastic agent that intercalates into DNA and inhibits topoisomerase II, leading to DNA strand breaks and apoptosis. - Raltitrexed is a folate analog that directly inhibits thymidylate synthase, further blocking DNA synthesis. This combination targets rapidly dividing cancer cells through multiple mechanisms affecting nucleotide synthesis and DNA integrity. It has been studied in advanced solid tumors including gastrointestinal cancers[10][7][8].