Direct-acting Antiviral Agents for the Treatment of Chronic Hepatitis C Virus Infection.

Hepatitis C virus (HCV) is a leading cause of cirrhosis and hepatocellular carcinoma (HCC) in the US and Japan. Therefore, eradication of HCV may reduce the occurrence of HCC in HCV-infected individuals. In 2011, the use of first-generation HCV NS3/4A protease inhibitors such as telaprevir and boceprevir was initiated for clinical treatment of HCV. Administration of telaprevir and boceprevir plus peginterferon and ribavirin increased rates of sustained virological response (SVR) in HCV genotype 1-infected patients. However, this treatment regimen also led to severe adverse events. Second-generation direct-acting antiviral agents (DAAs) for HCV, such as simeprevir plus peg-interferon and ribavirin also resulted in higher SVR rates, with similar adverse events to other peg-interferon and ribavirin treatments. Higher SVR rates in HCV genotype 1- and 2-infected patients were achieved with 12-16 weeks of sofosbuvir plus other class DAAs with/without ribavirin and 12 weeks of sofosbuvir plus ribavirin, respectively. For "difficult-to-treat" HCV-infected patients, more therapeutic options are needed. Further studies examining the efficacy and adverse effects of such therapies will be required for the development of additional treatments.