GSK PLC (LSE:GSK, NYSE:GSK) said on Wednesday that a potential new treatment for chronic hepatitis B had delivered positive late-stage trial results, raising the prospect of a shorter, more effective therapy for a disease that affects more than 250 million people worldwide.
The drug, bepirovirsen, met its primary goal in two large phase III trials, B-Well 1 and B-Well 2, with GSK saying it achieved a “statistically significant and clinically meaningful” functional cure rate when added to existing treatment. The studies involved more than 1,800 patients across 29 countries.
A functional cure in hepatitis B means the virus can no longer be detected in the blood for at least 24 weeks after treatment ends. Today’s standard drugs, known as nucleos(t)ide analogues, usually suppress the virus but rarely eliminate it, meaning many patients need to stay on medication for life. Functional cure rates with current therapies are typically about 1%.
GSK said patients receiving bepirovirsen alongside standard care were significantly more likely to reach this goal than those on standard treatment alone. The effect was even stronger in patients who entered the trials with lower levels of hepatitis B surface antigen, a key marker of ongoing infection.
The company added that the safety and tolerability profile of the drug was in line with earlier studies.
Tony Wood, GSK’s chief scientific officer, said: “Today’s result supports our plans to progress bepirovirsen as a treatment and also continue its development as a backbone in future sequential therapies.”
Chronic hepatitis B is a major cause of liver damage and accounts for about 56% of liver cancer cases globally. The condition is responsible for roughly 1.1 million deaths each year.
GSK said it plans to begin regulatory filings around the world from the first quarter of 2026. Full trial results will be presented at a scientific conference and published in a peer-reviewed journal.
If approved, bepirovirsen could become the first finite, six-month treatment for chronic hepatitis B, rather than a therapy taken indefinitely.