MSD KK, of Tokyo, on March 11 filed an application for approval of two oral agents for chronic hepatitis C elbasvir and grazoprevir hydrate in Japan. Elbasvir, an NS5A inhibitor, and grazoprevir hydrate, an NS3/4A protease inhibitor, are once-daily oral antiviral agents developed as agents for genotype 1 chronic hepatitis C with or without compensated cirrhosis. In the U.S., Zepatier, an oral combination agent of elbasvir and grazoprevir hydrate, was approved in Jan. 28, 2016, by the FDA for the treatment of genotype 1 and 4 chronic hepatitis C with or without compensated cirrhosis as monotherapy or in combination with ribavirin. (See BioWorld Today, Feb. 1, 2016.)