Antiviral Therapies and Prospects for a Cure of Chronic Hepatitis B

Current therapies of chronic hepatitis B (CHB) remain limited to either pegylated interferon-a (Peg-IFN-a), or one of the five approved nucleoside analog (NA) treatments. Although viral suppression can be achieved in the majority of patients with high-barrier-to-resistance newgenerationNAs (i.e., entecavir and tenofovir), HBsAg loss is achieved in only 10% of patients with both classes of drugs after a follow-up of 5 years. Attempts to improve the response by administering two different NAs or a combination of NA and Peg-IFN-a have been unsuccessful. Therefore, there is a renewed interest to investigate a number of steps in the hepatitis B virus (HBV) replication cycle and specific virus-host cell interactions as potential targets for new antivirals. Novel targets and compounds could readily be evaluated using both relevant in vitro and newly developed in vivo models of HBV infection. The addition of one or several newdrugs to current regimens should offer the prospect of markedly improving the response to therapy, thus reducing the burden of drug resistance, aswell as the incidence of cirrhosis and hepatocellular carcinoma (HCC).