Vol.63 No.3 May 2015
Current status of anti-viral drug development of anti-herpetic drug ASP2151 and anti-influenza drug T-705
Department of Virology, University of Toyama, 2630 Sugitani, Toyama, Japan
Abstract
An anti-herpetic drug, ASP2151 (amenamevir) and an anti-influenza drug, T-705 (favipiravir) have been developed in Japan. ASP2151 shows Helicase-primase inhibitory activity against the herpes simplex virus and varicella-zoster virus, and T-705 shows inhibitory activity against viral RNA synthesis with broad spectrum RNA viruses including influenza. ASP2151 is different from conventional anti-herpetic drugs via viral thymidine kinase and expected to prevent transmission of genital herpes based on the good profile of its pharmacokinetics. The anti-influenza drugs, neuraminidase inhibitors(NAIs), allow the growth of influenza virus in infected cells but inhibit the spread of infection to the surrounding area. On the other hand, T-705 inhibits viral RNA synthesis as a chain terminator. T-705 reduces the viral load by inhibiting viral RNA synthesis and does not produce resistant virus in the cultured cells, exhibiting excellent properties as an anti-viral drug. T-705 and NAI showed similar therapeutic activity in mild influenza infection. T-705 showed the efficacy in severe influenza infection, whereas oseltamivir failed to cure all animals in an influenza infection model, being expected as a last resort for influenza. T-705 will be approved in countries for the treatment of novel influenza, new H5 and such H7 epidemic infection, and seasonal influenza cases for which other anti-influenza virus agents are invalid, when it becomes authorized for use as determined by the regulatory agency of each country. The efficacy of T-705 has been confirmed in animal models against RNA viruses such as Ebola and yellow fever based on the commonality of viral RNA synthesis inhibition of the RNA viruses.
Key word
antiviral agents, nucleic acid synthesis inhibitor, herpes virus, influenza virus
Received
November 12, 2014
Accepted
March 4, 2015
Jpn. J. Chemother. 63 (3): 330-338, 2015
