GSK (LSE:GSK) announced positive pivotal Phase 3 results for bepirovirsen in chronic hepatitis B, with a pooled functional cure rate of 19% in the overall population (233 of 1,220 vs 0 of 614 placebo) and 26% in patients with baseline HBsAg ≤1000 IU/ml (200 of 768 vs 0 of 393), meeting primary and key secondary endpoints.
The two global, randomised, placebo‑controlled B‑Well trials (B‑Well 1 and B‑Well 2) were published in the New England Journal of Medicine and presented at EASL, GSK said.
In exploratory analyses 49% of bepirovirsen recipients achieved qHBsAg ≤100 IU/ml one year after end of treatment, and 23% of recipients achieved sustained HBV DNA
The safety profile was described as acceptable and consistent with prior studies, with the most frequent adverse events being injection site erythema, local pain and transient increases in a liver enzyme.
Bepirovirsen is under priority review by the US FDA with Breakthrough and Fast Track designations, is also under review in Europe, Japan and China, and GSK has a strategic collaboration with Sino Biopharmaceutical to support launch in China.
“For the first time, bepirovirsen offers the possibility of significantly better functional cure rates than the current standard of care, and the potential to reduce the risk of long-term liver complications, including cancer,” said Tony Wood, GSK’s Chief Scientific Officer.
GSK anticipates the first regulatory decisions in Q3 2026 and said launch preparations are underway.
