arfolitixorin + pemetrexed

This drug is a **combination of arfolitixorin and pemetrexed**. - **Arfolitixorin** is an immediately active folate ([6R]-5,10-methylene-tetrahydrofolate), designed to enhance the efficacy of 5-fluorouracil (5-FU)-based chemotherapy by providing direct active folate supplementation, as opposed to using precursors like leucovorin. Its principal mechanism is as a biochemical modulator of 5-FU by providing reduced folate required for optimal inhibition of thymidylate synthase. - **Pemetrexed** is a multi-target **antifolate antimetabolite chemotherapy** agent that inhibits several folate-dependent enzymes in the de novo purine and pyrimidine synthesis pathways, most notably **thymidylate synthase**, **dihydrofolate reductase**, and **glycinamide ribonucleotide formyltransferase**, leading to disruption of DNA and RNA synthesis and resulting in cell cycle arrest and cell death, primarily in rapidly proliferating tumor cells[1][3]. - The combination has not been described as a standard regimen, but both agents are investigated and/or used in the treatment of **malignancies such as metastatic colorectal cancer and non-small cell lung cancer**, either alone or in combination with other cytotoxics. - Arfolitixorin is being developed to optimize folate modulation in chemotherapy; pemetrexed is approved for cancers such as non-squamous non-small cell lung cancer and malignant pleural mesothelioma[1][3].