A nucleoside analog. Pyrazofurin potently inhibits orotidine 5'-monophosphate (OMP) decarboxylase, thereby interfering with de novo synthesis of uridine nucleotides and resulting in cytotoxicity. This agent also causes a rapid depletion of the pyrimidine deoxynucleotide pool, thereby inhibiting DNA synthesis and cell replication. Check foractive clinical trials using this agent.