Existing and future therapeutic options for hepatitis C virus infection.

Hepatitis C virus (HCV) infection is an important cause of chronic hepatitis, cirrhosis, hepatocellular carcinoma and liver failure worldwide. Chronic hepatitis C virus infection is treated with interferon-a (IFN-α), pegylated interferon-α (PEG-IFNα) alone or in combination with ribavirin; however, a significant fraction of patients either fail to respond or relapse after cessation of therapy. Efforts to identify and develop highly specific and potent HCV inhibitors have intensified recently. Each of the virally encoded replication enzymes has been a focus of studies as well as viral receptors and the host immune system. This review summarizes recent progress in the search for novel anti-HCV agents.