Vol.65 No.5 September 2017
Favipiravir, viral RNA polymerase inhibitor
Business Development Department, Toyama Chemical Co. Ltd., 2-4-1 Shimookui, Toyama, Japan
Abstract
Favipiravir (T-705; 6-fluoro-3-hydroxy-2-pyrazine carboxamide) was discovered through screening a chemical library for anti-viral activity against influenza viruses by Toyama Chemical Co., Ltd. Favipiravir is a novel anti-viral drug that selectively and potently inhibits the RNA-dependent RNA polymerase (RdRp) of RNA viruses. It is phosphoribosylated by cellular enzymes to its active form, favipiravir ribofuranosyl-5'-triphosphate, which is recognized as a substrate by RdRp, and inhibits the RNA polymerase activity. Since the catalytic domain of RdRp is conserved among various types of RNA viruses, this phenomenon of action is supported by evidence from a broader spectrum of anti-viral activities of favipiravir in vitro and in vivo. Favipiravir is effective against a wide range of types and subtypes of influenza viruses, including strains resistant to existing anti-influenza drugs. Of note is that favipiravir shows anti-viral activities against other RNA viruses such as Arenaviruses, Bunyaviruses and Filoviruses, all of which are known to cause fatal hemorrhagic fever. Such a unique anti-viral profile will make favipiravir a potentially promising drug for untreated infections by RNA viruses.
Key word
favipiravir, antivirals, influenza virus, RNA virus, RNA-dependent RNA polymerase
Received
February 24, 2017
Accepted
March 15, 2017
Jpn. J. Chemother. 65 (5): 736-744, 2017
