Favipiravir (T-705) inhibits in vitro norovirus replication.

Human noroviruses are the primary cause of foodborne gastroenteritis. Potent and safe inhibitors are needed for the treatment/prophylaxis of norovirus infections. We demonstrate that Favipiravir [T-705, a drug in advanced clinical development for the treatment of infections with the influenza virus] inhibits in vitro murine norovirus replication. Time-of-drug addition studies reveal that T-705 exerts its activity at a time-point that coincides with onset of viral RNA synthesis, which is in line with the viral polymerase as the presumed target.