FDA approval of bepirovirsen for hepatitis B

The U.S. Food and Drug Administration (FDA) has approved Hibsago (bepirovirsen), an injection developed by GSK, for treating chronic hepatitis B virus (HBV) infection in certain adults without cirrhosis. As the first antisense oligonucleotide approved for this purpose, the medication targets the genetic instructions used by the virus to replicate and produce viral proteins.

The treatment is intended for patients who have undergone at least six months of antiviral therapy and exhibit suppressed HBV levels alongside hepatitis B surface antigen (HBsAg) levels of 3,000 IU/mL or less. The FDA also authorized the Roche Elecsys HBsAg II quant II RxDx test to assist in patient selection and monitoring.

Clinical data indicates that 19% of patients achieved a functional cure, defined as having undetectable HBsAg 24 weeks after stopping all antiviral therapy. This rate significantly exceeds the less than 1% functional cure rate observed with conventional treatments. Achieving a functional cure is considered a major milestone, as it may allow patients to potentially cease lifelong medication and reduces long-term risks of cirrhosis and liver cancer.