GSK drug shows promise as a hepatitis B cure in trials

Chronic hepatitis B still affects 254 million people and killed an estimated 1.1 million people in 2022, mostly through cirrhosis and liver cancer. In 2024, viral hepatitis B and C together were still responsible for about 1.3 million deaths, while fewer than 5% of people living with chronic hepatitis B were receiving treatment. The virus can spread from mother to baby at birth, through blood and other body fluids, and it remains preventable with vaccination, but the global burden is still concentrated in communities where testing, long-term care and follow-up remain out of reach for many families.

That is what makes GSK’s bepirovirsen a potential cure rather than a finished breakthrough. In the B-Well 1 and B-Well 2 phase III trials, more than 1,800 patients from 29 countries took part, and the drug produced functional cure rates of about 20% and 19%, with no placebo patient reaching that endpoint. GSK defines functional cure as sustained loss of hepatitis B surface antigen and undetectable HBV DNA for at least 24 weeks after treatment ends, which means the signal is promising but still not the same as proving the virus will stay controlled for years.

The results stand out because current nucleos(t)ide analogue therapy often means lifelong medication and still produces functional cure in only about 1% of patients. GSK said chronic hepatitis B accounts for about 56% of liver cancer cases worldwide, a reminder that even a modest increase in durable remission could change the risk of liver cancer for millions of people. The attraction of bepirovirsen is not just the response rate, but the possibility of a finite six-month treatment course that could reset treatment goals for a disease long managed, not cured.

Regulators have already pushed the medicine toward a possible launch. The U.S. Food and Drug Administration accepted bepirovirsen for priority review on April 28, 2026 and set an October 26, 2026 PDUFA date, while GSK said the drug was also under review in Europe, China and Japan. If approvals come through, the first access would likely start in the United States and other specialist hepatology settings before broader rollout, leaving pricing and reimbursement to decide how quickly the benefit reaches patients beyond the trial centers.

The access question is already shaping the rollout. In China, GSK said it struck a collaboration with SBP Group to accelerate bepirovirsen at launch through more than 5,000 medical centres, showing that distribution networks will matter as much as clinical data if the drug is to reach people at highest risk of liver cancer. For the millions living with chronic hepatitis B in lower-resource settings, the difference between a scientific milestone and a public health advance will come down to who can actually get the drug, and whether health systems can afford to deliver it at scale.