calcium folinate + fluorouracil + hydroxycamptothecin + tumor necrosis factor

This is a four-drug combination regimen consisting of calcium folinate (also known as folinic acid or leucovorin), fluorouracil (5-fluorouracil, 5-FU), hydroxycamptothecin, and tumor necrosis factor. - Calcium folinate is a reduced form of folic acid used to enhance the efficacy and reduce the toxicity of certain chemotherapy agents, particularly fluorouracil. It stabilizes the binding of 5-fluorodeoxyuridine monophosphate to thymidylate synthase, thereby enhancing inhibition of DNA synthesis in cancer cells[4][5][8]. - Fluorouracil is an antimetabolite chemotherapeutic agent that inhibits thymidylate synthase, disrupting DNA synthesis and leading to cell death in rapidly dividing cells[2][4][5]. - Hydroxycamptothecin is a plant-derived alkaloid that acts as a topoisomerase I inhibitor, causing DNA damage during replication and inducing apoptosis in cancer cells[7][10]. It has demonstrated broad-spectrum antitumor activity against various solid tumors including colorectal cancer[7][10]. - Tumor necrosis factor (TNF) is a cytokine with direct cytotoxic effects on tumor cells and can modulate immune responses against tumors. TNF has been explored for its ability to induce hemorrhagic necrosis within tumors but its systemic use is limited by significant toxicity. This combination targets multiple pathways involved in tumor growth—DNA synthesis inhibition (fluorouracil/calcium folinate), topoisomerase I inhibition (hydroxycamptothecin), and immune/cytokine-mediated cytotoxicity (tumor necrosis factor). The regimen would be considered investigational; while combinations such as FOLFIRI or FOLFOX are established for colorectal cancer treatment, there are no widely recognized regimens combining all four agents together.