Emerging therapeutics for chronic hepatitis B.

Hepatitis B is a global health problem. Patients with chronic hepatitis B (CHB) carry a significant risk to eventually develop cirrhotic liver disease. Recent therapeutic advances against CHB offer excellent potential for long-term suppression of hepatitis B virus (HBV) replication during antiviral therapy, and occasionally a durable remission off medication. Selection of appropriate patients for antiviral therapy depends on identification of HBV replication and an elevated alanine aminotransferase level or histologic liver injury. Pegylated interferon alpha offers potent immunomodulatory and antiviral activity with the potential for durability, but also with adverse effects and significant cost. The nucleoside or nucleotide analogs, lamivudine, adefovir, and entecavir, suppress HBV replication and are extremely well-tolerated, but long-term or even lifelong therapy is required. Most experience has been gained with lamivudine, but viral resistance occurs frequently. Newer analogs appear to be relatively free of this problem. Approaches using a combination of agents have promise, but have yet to be proven superior to individual drugs alone.