- Phase III B‑Well 1/2 pooled: 6‑month bepirovirsen achieved 19% functional cure (HBsAg ≤3000 IU/mL) and 26% in the ≤1000 IU/mL subgroup versus 0% on standard of care.
- Exploratory outcomes: 49% of recipients reached qHBsAg ≤100 IU/mL one year after end of treatment, and 23% had HBV DNA
- Bepirovirsen is an antisense oligonucleotide licensed from Ionis and developed by GSK; regulatory reviews are ongoing with FDA (Breakthrough/Fast Track), EMA, Japan (SENKU) and China (Breakthrough/Priority), with first decisions expected Q3 2026.
- GSK has a strategic collaboration with Sino Biopharmaceutical to accelerate patient access at launch in China and launch preparations are underway.
Trial results
Pooled Phase III B‑Well 1/2 data show 6‑month bepirovirsen plus standard care achieved 19% functional cure in participants with baseline HBsAg ≤3000 IU/mL (233/1,220 vs 0/614 placebo) and 26% in the ≤1000 IU/mL subgroup (200/768 vs 0/393); exploratory analysis found 49% reached qHBsAg ≤100 IU/mL one year after end of treatment, and 23% had HBV DNA
Clinical significance
Functional cure is defined as undetectable HBsAg and HBV DNA
Safety and study design
The trials were randomized, double‑blind, placebo‑controlled, conducted across 29 countries in adults on nucleos(t)ide analogue therapy with baseline HBsAg ≤3000 IU/mL; safety was described as acceptable with most common adverse events being injection‑site erythema, local pain and transient rises in liver enzymes.
Regulatory and commercial status
Bepirovirsen is an antisense oligonucleotide licensed from Ionis; regulatory reviews are underway (FDA Breakthrough and Fast Track, EMA, Japan SENKU, China Breakthrough/Priority) with first decisions anticipated in Q3 2026, and a collaboration with Sino Biopharmaceutical aims to speed access in China.
