- EMA accepted GSK's marketing authorisation application for bepirovirsen (antisense oligonucleotide) for chronic hepatitis B on 27 March 2026
- Phase III B-Well 1 and 2 (29 countries) met their primary endpoint: bepirovirsen plus nucleos(t)ide analogues produced statistically significant, clinically meaningful functional cure rates versus standard of care, with larger effect in patients with baseline HBsAg <=1000 IU/ml
- Bepirovirsen, licensed from Ionis, targets HBV mRNA/pregenomic RNA to lower HBsAg and inhibit replication, is not approved anywhere, and pivotal data will be presented and submitted for publication in 2026
Regulatory submission
On 27 March 2026 the European Medicines Agency accepted GSK's marketing authorisation application for bepirovirsen, an investigational antisense oligonucleotide, for treatment of adults with chronic hepatitis B.
Phase III B‑Well programme
B‑Well 1 and 2 were global, randomised, double‑blind, placebo‑controlled trials across 29 countries assessing nucleos(t)ide analogue‑treated CHB patients with baseline HBsAg ≤3000 IU/ml; both met their primary endpoint, showing statistically significant and clinically meaningful higher functional cure rates for bepirovirsen plus standard of care versus standard of care alone, with a larger effect in patients with baseline HBsAg ≤1000 IU/ml; safety and tolerability were reported as acceptable and pivotal data will be presented and submitted for peer‑review in 2026.
Disease burden
About 3.2 million people in Europe live with chronic hepatitis B and ~250 million worldwide; CHB causes roughly 1.1 million deaths annually globally and an estimated 15,000 deaths in Europe; current nucleos(t)ide analogue therapy often requires lifelong treatment and yields functional cure rates around 1%.
Drug profile and development
Bepirovirsen is a triple‑action ASO designed to target HBV mRNA and pregenomic RNA to lower HBsAg, inhibit viral replication and stimulate immune responses; it was licensed from Ionis Pharmaceuticals, is not approved anywhere, and is being evaluated as a potential backbone for sequential strategies to expand functional cure to broader populations.
