Drug Discovery Study Aimed at a Functional Cure for HBV

Hepatitis B virus (HBV) causes acute and, most importantly, chronic hepatitis B worldwide. Antiviral treatments have been developed to reduce viral loads but few patients with chronic hepatitis B (CHB) achieve a functional cure. The development of new therapeutic agents is desirable. Recently, many novel agents have been developed, including drugs targeting HBV-DNA and HBV-RNA. This review provides an overview of the developmental status of these drugs, especially direct acting antiviral agents (DAAs). Serological biomarkers of HBV infection are essential for predicting the clinical course of CHB. It is also important to determine the amount and activity of covalently closed circular DNA (cccDNA) in the nuclei of infected hepatocytes. Hepatitis B core-associated antigen (HBcrAg) is a new HBV marker that has an important role in reflecting cccDNA in CHB, because it is associated with hepatic cccDNA, as well as serum HBV DNA. The highly sensitive HBcrAg (iTACT-HBcrAg) assay could be a very sensitive HBV activation marker and an alternative to HBV DNA testing for monitoring reactivation. Many of the drugs currently in clinical trials have shown efficacy in reducing hepatitis B surface antigen (HBsAg) levels. Combination therapies with DAAs and boost immune response are also under development; finding the best combinations will be important for therapeutic development.

Automated summary

Hepatitis B virus (HBV) is a significant cause of acute and chronic hepatitis worldwide. Current antiviral treatments do not always lead to a functional cure for chronic hepatitis B (CHB), so there is a need for new therapeutic agents. This review provides an overview of the developmental status of these drugs, particularly direct acting antiviral agents (DAAs), and highlights the importance of serological biomarkers and the measurement of covalently closed circular DNA (cccDNA) for predicting and monitoring CHB. Combination therapies and boosting immune response are also being explored.