Positive phase III data from Ionis Pharmaceuticals and GSK plc support bepirovirsen as a potential new treatment for chronic hepatitis B. The global B-Well 1 and B-Well 2 studies met their primary endpoint, demonstrating statistically significant and clinically meaningful functional cure rates compared with standard of care alone.
These findings mark a major advance in a field where no approved therapies currently achieve durable functional cure. Full results will be presented at a forthcoming scientific congress and submitted to regulatory authorities worldwide.
Phase III B-Well trials meet primary endpoint
The B-Well 1 (NCT05630807) and B-Well 2 (NCT05630820) trials enrolled more than 1,800 participants across 29 countries. Both studies evaluated the efficacy and safety of bepirovirsen added to standard of care in nucleos(t)ide analogue-treated patients with chronic hepatitis B.
Bepirovirsen demonstrated significantly higher functional cure rates than standard of care alone across all ranked endpoints. The treatment effect was particularly pronounced in participants with baseline hepatitis B surface antigen (HBsAg) levels ≤1,000 IU/ml. Functional cure was defined as sustained loss of HBsAg and undetectable HBV DNA for at least 24 weeks following completion of a finite treatment course.
The trials also showed an acceptable safety and tolerability profile, consistent with previous clinical studies of bepirovirsen.1,2
What the phase III results mean for chronic hepatitis B
“Chronic hepatitis B is one of the most common and persistent viral infections globally, yet no approved therapies can currently achieve meaningful functional cure,” said Dr Brett P. Monia, Chief Executive Officer, Ionis Pharmaceuticals. “Bepirovirsen is uniquely positioned to treat CHB by reducing viral replication, suppressing hepatitis B surface antigen and stimulating immune responses. These results demonstrate its potential to bring hope to millions of people living with the disease.”1
Tony Wood, Chief Scientific Officer, GSK, added: “Bepirovirsen has the potential to transform treatment goals for people living with CHB by achieving significant functional cure rates – a first for the disease. CHB affects more than 250 million people and leads to approximately 56% of liver cancer cases worldwide. Today’s result supports our plans to progress bepirovirsen as a treatment and also continue its development as a backbone in future sequential therapies. We’re pleased by this major advance in our expanding hepatology pipeline, aimed to transform outcomes in liver disease.”2
Implications for chronic hepatitis treatment
If approved, bepirovirsen could become the first finite, six-month therapeutic option for chronic hepatitis B and may form the foundation of future combination or sequential treatment approaches. Full trial data will be presented at an upcoming scientific meeting and published in a peer-reviewed journal, supporting planned regulatory submissions globally.1,2
Trial design overview
B-Well 1 and B-Well 2 were randomized, double-blind, placebo-controlled, multicentre phase III trials. They assessed efficacy, safety, pharmacokinetics and durability of functional cure in patients with baseline HBsAg ≤3,000 IU/ml, with a key secondary analysis in those with HBsAg ≤1,000 IU/ml.1,2
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This content has been developed independently by Touch Medical Media for touchINFECTIOUS DISEASES. Views expressed are the speaker’s own and do not necessarily reflect the views of Touch Medical Media.
Editor: Katey Gabrysch, Editorial Director.
Disclosures: This short article was prepared by touchINFECTIOUS DISEASES. The content was developed and edited by human editors. No fees or funding were associated with its publication. touchINFECTIOUS DISEASES utilize AI as an editorial tool (ChatGPT (GPT-4o) [Large language model]. https://chat.openai.com/chat).
Cite: Bepirovirsen achieves functional cure in phase III B-Well trials for chronic hepatitis B. touchINFECTIOUS DISEASES. 08 January 2026.
References:
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Yahoo Finance. Ionis partner GSK announces positive results from two pivotal phase III trials of bepirovirsen for chronic hepatitis B. Available at: https://uk.finance.yahoo.com/news/ionis-partner-gsk-announces-positive-071500716. Accessed 8 January 2026.
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GSK. GSK announces positive results from B-Well 1 and B-Well 2 phase III trials for bepirovirsen, a potential first-in-class treatment for chronic hepatitis B. Available at: https://www.gsk.com/en-gb/media/press-releases/gsk-announces-positive-results-from-b-well-1-and-b-well-2-phase-iii-trials-for-bepirovirsen-a-potential-first-in-class-treatment-for-chronic-hepatitis-b/. Accessed 8 January 2026.
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