valtoricitabine

Valtoricitabine is an orally bioavailable valine ester prodrug of the nucleoside analogue toricitabine (L-deoxycytidine), developed for the treatment of chronic hepatitis B virus (HBV) infection. Upon ingestion, valtoricitabine is rapidly converted by intestinal and hepatic esterases into toricitabine, which is subsequently phosphorylated by cellular kinases to its active 5'-triphosphate form. This active metabolite serves as a potent and selective inhibitor of the HBV DNA polymerase, competing with the natural substrate deoxycytidine triphosphate (dCTP) for incorporation into the nascent viral DNA strand. Incorporation results in DNA chain termination, effectively halting viral replication. Although valtoricitabine demonstrated significant antiviral activity in Phase 2 clinical trials, its development was ultimately terminated by Idenix and its partner Novartis.

Other names

L-deoxycytidine valine estervalyl-L-deoxycytidine