GSK announced on January 7, 2026, positive topline results from the two pivotal Phase III trials, B-Well 1 (NCT05630807) and B-Well 2 (NCT05630820), evaluating bepirovirsen, an investigational triple-action antisense oligonucleotide (ASO), as a potential first-in-class finite treatment for chronic hepatitis B (CHB). The randomized, double-blind trials enrolled over 1,800 virologically suppressed patients from 29 countries with CHB on stable nucleos(t)ide analogue (NA) therapy and baseline hepatitis B surface antigen (HBsAg) levels ≤3000 IU/mL. Participants received a six-month course of bepirovirsen added to ongoing NA therapy or continued NA alone.
Both trials met their primary endpoint: a statistically significant and clinically meaningful higher proportion of patients achieving functional cure—defined as sustained loss of HBsAg and undetectable HBV DNA for at least 24 weeks post-treatment—with bepirovirsen plus NA compared to NA alone. All ranked secondary endpoints were also met with statistical significance, including enhanced effects in the subgroup with baseline HBsAg ≤1000 IU/mL. Bepirovirsen exhibited an acceptable safety and tolerability profile, consistent with prior studies, supporting its potential as a backbone for future sequential therapies aimed at higher cure rates.
Chronic hepatitis B affects more than 250 million people worldwide and is a leading cause of liver cancer, accounting for approximately 56% of cases globally. Current lifelong NA therapies suppress viral replication but rarely achieve functional cure, leaving patients at ongoing risk of disease progression.
Full data will be presented at an upcoming scientific congress and submitted for peer-reviewed publication. GSK intends to advance global regulatory filings from the first quarter of 2026. This milestone positions bepirovirsen as a potential transformative finite therapy addressing a major unmet need in hepatology.
