Abstract: Hepatitis C virus infection is one of the leading causes of cirrhosis, hepatocellular carcinoma and liver failure. The current standard of care, a combination of Peg-IFN and ribavirin, eradicates the virus in only about 50% of patients. Direct-acting antiviral agents(DAAs) are in phase Ⅰ, Ⅱ and Ⅲ trials, which target the nonstructural 3 protease, the NS5A protein, the RNA-dependent RNA-polymerase NS5B. They directly inhibit HCV replication through interaction with host cell protein. Because of the high genetic heterogeneity of HCV and its rapid replication, monotherapy with DAAs possess a high risk for selection of resistant variants. This article reviews the progress in the research, resistance profiles and parameters of DAAs.

Key words: hepatitis C virus, direct-acting antiviral, resistance