Overview
- GSK’s Hibsago (bepirovirsen) won U.S. approval Oct. 20 based on pooled Phase 3 B‑Well 1 and 2 data showing a 19% functional cure rate at 24 weeks off treatment versus 0% for placebo.
- The drug is indicated for adults without cirrhosis who have taken nucleos(t)ide analogue therapy for at least six months, have suppressed HBV DNA, and have HBsAg levels of 3,000 IU/mL or less as measured by an FDA‑authorized test.
- The approved regimen is weekly subcutaneous injections for up to 24 weeks given with existing antivirals, with patients required to continue antivirals for at least 24 weeks after the final dose and to follow specific stop rules.
- Prescribing information carries a boxed warning for on‑treatment hepatic flares and thrombocytopenia and requires close lab monitoring including weekly platelet checks and regular ALT and bilirubin tests with defined thresholds for permanent discontinuation.
- The approval includes Roche’s authorized Elecsys HBsAg II quant II RxDx companion assay, follows earlier Japanese approval, and could shift care for a subset of patients who now may avoid indefinite antivirals while regulators in China and Europe complete reviews.