- NMPA accepted an NDA for bepirovirsen in China on 30 Mar 2026 following Phase III B-Well trial results.
- B-Well 1 and 2 (global, 29 countries) showed statistically significant, clinically meaningful functional cure rates in NA-treated non‑cirrhotic CHB patients, with primary endpoint in those with baseline HBsAg ≤3000 IU/ml and a key secondary in ≤1000 IU/ml.
- Bepirovirsen is a triple-action antisense oligonucleotide targeting HBV mRNA and pregenomic RNA, licensed by GSK from Ionis, granted Breakthrough Therapy in China (Aug 2021) and not yet approved anywhere.
Regulatory filing
On 30 March 2026 the China NMPA accepted a new drug application for bepirovirsen for adults with chronic hepatitis B, supported by pivotal Phase III B‑Well results; bepirovirsen received Breakthrough Therapy designation in China in August 2021.
Phase III B‑Well trials
B‑Well 1 and B‑Well 2 were global, randomized, double‑blind, placebo‑controlled trials in 29 countries assessing nucleos(t)ide analogue‑treated, non‑cirrhotic participants with baseline HBsAg ≤3000 IU/ml; the primary endpoint was functional cure in the ≤3000 IU/ml cohort with a key secondary in ≤1000 IU/ml. Bepirovirsen plus standard of care produced statistically significant and clinically meaningful higher functional cure rates versus standard of care alone, with greater effects in patients with lower baseline HBsAg; safety and tolerability were consistent with prior studies. Data will be presented at a congress and submitted for peer‑reviewed publication in 2026.
Mechanism and development
Bepirovirsen is a triple‑action antisense oligonucleotide designed to target HBV mRNA and pregenomic RNA, inhibiting viral replication, reducing HBsAg levels and stimulating immune responses; GSK licensed the candidate from Ionis. It holds regulatory designations including US Fast Track and Japan SENKU and is not yet approved anywhere.
Disease burden
Chronic hepatitis B affects more than 250 million people worldwide and an estimated 75 million in China, causes about 1.1 million deaths annually (≈450,000 in China), and current nucleos(t)ide analogue therapy yields low functional cure rates (around 1%).
