New therapies for chronic hepatitis B.

Currently, the only therapy of proven benefit in chronic hepatitis B is interferon-alpha which leads to a long-term benefit in only one-third of patients. New therapies for hepatitis B fall into three categories; antiviral chemotherapy, immunomodulation with cell-based therapies, vaccines or cytokines, and gene therapy such as with antisense oligonucleotides, ribozymes or viral mutants. The most promising immediate approach to therapy is with the new nucleoside antivirals--lamivudine and famciclovir. These drugs are well absorbed orally, result in profound inhibition of circulating hepatitis B virus, and, in some cases, loss of hepatitis B e antigen and improvement in serum aminotransferases. Controlled trials of long-term famciclovir and lamivudine therapy currently underway aim to show whether these drugs are safe and can provide sustained inhibition of viral replication and attentant improvement in liver disease.