The US Food and Drug Administration (FDA) has approved British pharmaceutical company GSK’s hepatitis B drug Hibsago, giving patients with the chronic liver infection a chance to keep the virus under control after stopping treatment.

The medicine, chemically known as bepirovirsen, is the first FDA-approved antisense oligonucleotide for chronic hepatitis B. It reduces the production of HBV-associated RNA and viral proteins, suppresses hepatitis B surface antigen (HBsAg) levels in the blood, and may stimulate the immune system to increase the chances of a durable, sustained response.

In clinical trials, nearly one in five patients who received bepiruvirsen achieved undetectable hepatitis B virus levels and remained off antiviral treatment for at least six months. The B-Well 1 and B-Well 2 trials are global multi-centre, randomised, double-blind, placebo-controlled trials conducted in 29 countries.

Hepatitis B is a viral infection that can cause both acute and chronic liver disease. Chronic hepatitis B occurs when the immune system is unable to clear the virus, resulting in long-lasting infection that affects more than 240 million people worldwide. The disease causes approximately 1.1 million deaths each year and is the leading cause of liver cancer cases globally. Existing standard treatments help only 1% to 4% of patients clear the virus for a sustained period, or achieve what doctors call a functional cure.

It is to be noted that Hibsago (bepirovirsen) has already been approved in Japan and is currently under regulatory review in China and Europe.