T-705 (Favipiravir) is an antiviral drug that selectively inhibitsthe RNA-dependent RNA polymerase of influenza virus. It isphosphoribosylated by cellular enzymes to its active form,favipiravir-ribofuranosyl-5"-triphosphate (RTP). Favipiravir isactive against a broad range of influenza viruses, includingA(H1N1)pdm09, A(H5N1) and the recently emerged A(H7N9)avian virus. It also inhibits influenza strains resistant to currentantiviral drugs, and shows a synergistic effect in combinationwith oseltamivir, thereby expanding influenza treatmentoptions. Recently, T-705 has been shown to give 100%protection against aerosol Ebola virus E718 infection inimmune-deficient mice as well as inhibiting Ebola virusinfection in cell culture.