Definition

A 2,2′-anhydropyrimidine derivative and human uridine phosphorylase (UPase) inhibitor that can be used to suppress mucositis induced by certain chemotherapeutics. Upon administration of UPase inhibitor TK-112690 prior to the administration of certain chemotherapeutic agents, such as methotrexate (MTX), this agent targets, binds to and blocks the activity of UPase, thereby preventing the metabolic breakdown of uridine into uracil. This increases the uridine levels in plasma and may prevent mucositis. By rescuing normal tissue, TK-112690 may enhance the therapeutic index of the chemotherapeutic agent. UPase plays a key role in in pyrimidine metabolism, and catabolizes uridine into uracil and ribose-1-phosphate.