3-Deazauridine (NSC 126849): an interesting modulator of biochemical response

3-Deazauridine (NSC 126849) is a structural analog of uridine that inhibits the biosynthesis of Cytidine-5'-Triphosphate by competitive inhibition of Cytidine Triphosphate synthetase which is considered to be the primary mode of action of this nucleoside analog. Despite a paucity of clinical attention given to this drug as a single agent, it has generated much enthusiasm as a biological response modulator because of its synergistic effect with a number of antitumor agents including Cytosine Arabinoside, 5-aza-2'-deoxycytidine, 5-azacytidine, thymidine and D-galactosamine, although only the cytosine arabinoside/3-Deazauridine combination has been explored clinically. In this paper, the current status of the drug and future perspectives will be discussed.