GSK plc’s bepirovirsen MAA accepted by the European Medicines Agency for chronic hepatitis B, supported by positive Phase III B-Well trial data showing improved functional cure rates.
Written By: Vennela Reddy, BPharm
Reviewed By: Pharmacally Editorial Team
GSK plc has announced that the European Medicines Agency has accepted its marketing authorisation application (MAA) for bepirovirsen, an investigational antisense oligonucleotide, for the treatment of adults with chronic hepatitis B (CHB).
The submission is supported by positive Phase III data from the B-Well 1 (NCT05630807) and B-Well 2 (NCT05630820) trials, where bepirovirsen demonstrated statistically significant and clinically meaningful improvements in functional cure rates compared with standard of care alone. Both trials met their primary endpoints, with consistent efficacy across all ranked endpoints. Notably, patients with baseline hepatitis B surface antigen (HBsAg) ≤1000 IU/ml showed an even greater treatment effect.
Bepirovirsen was evaluated in combination with nucleos(t)ide analogues, the current standard therapy, which typically requires lifelong administration and achieves functional cure in only about 1% of patients. In contrast, bepirovirsen-based therapy significantly increased the proportion of patients achieving functional cure, defined as sustained loss of HBsAg and undetectable HBV DNA for at least 24 weeks after completing treatment.
The safety and tolerability profile of bepirovirsen was consistent with previous studies, supporting its potential as a finite-duration therapeutic option. Detailed results are expected to be presented at a scientific congress and submitted for peer-reviewed publication in 2026.
Chronic hepatitis B remains a major public health burden, affecting an estimated 3.2 million people in Europe and over 250 million globally. The disease is a leading cause of liver-related mortality, contributing to approximately 1.1 million deaths annually and accounting for around 56% of liver cancer cases worldwide. Achieving functional cure is widely recognised, including by the European Association for the Study of the Liver, as the ultimate goal of CHB treatment.
Bepirovirsen is a triple-action antisense oligonucleotide designed to target hepatitis B viral RNA, leading to degradation of viral genetic material, suppression of hepatitis B surface antigen, and stimulation of immune control. By addressing multiple aspects of viral persistence, it aims to enable durable off-treatment responses.
The B-Well clinical programme consisted of global, randomised, double-blind, placebo-controlled Phase III trials conducted across 29 countries in nucleos(t)ide analogue-treated patients with CHB. The studies evaluated efficacy, safety, pharmacokinetics, and durability of response in patients with baseline HBsAg ≤3000 IU/ml.
Bepirovirsen is also being explored as a potential backbone therapy for future sequential regimens aimed at expanding functional cure to broader patient populations.
The therapy was licensed from Ionis Pharmaceuticals, with whom GSK collaborated on development. Bepirovirsen is currently not approved in any market.
References
Study of Bepirovirsen in Nucleos(t)Ide Analogue-treated Participants with Chronic Hepatitis B (B-Well 1) (B-Well 1), ClinicalTrials.gov ID NCT05630807, https://clinicaltrials.gov/study/NCT05630807
Study of Bepirovirsen in Nucleos(t)Ide Analogue-treated Participants with Chronic Hepatitis B (B-Well 2) (B-Well 2), ClinicalTrials.gov ID NCT05630820, https://clinicaltrials.gov/study/NCT05630820
Bepirovirsen accepted for review by the European Medicines Agency as a potential first-in-class treatment for chronic hepatitis B, 27 March 2026, Bepirovirsen accepted for review by the European Medicines Agency as a potential first-in-class treatment for chronic hepatitis B | GSK