OSI-7904L (GW1843) is a noncompetitive inhibitor of thymidylate synthase (TS). OSI-7904L is an antifolate compound and a substrate for folylpolyglutamate synthetase. OSI-7904L has cytotoxicity against solid tumor lines, and the toxicity can be selectively blocked by folic acid[1].
[1] Schwartz G, et al. A phase I and pharmacokinetic study of 1843U89, a noncompetitive inhibitor of thymidylate synthase, in patients with advanced solid malignancies. Clin Cancer Res. 2001 Jul;7(7):1901-11. PMID:11448903
