Overview
- The FDA approved Hibsago (bepirovirsen) on Tuesday, Oct. 20, 2026, making it the first antisense oligonucleotide cleared in the United States for chronic hepatitis B.
- Hibsago is given as weekly subcutaneous injections for up to 24 weeks alongside existing antiviral therapy and patients must remain on antivirals for at least 24 weeks after the final dose before any discontinuation is considered.
- Approval was based on two Phase 3 trials that enrolled more than 1,800 people across 29 countries and found 24% of treated patients met criteria to stop antivirals and 19% maintained viral control 24 weeks after stopping treatment.
- The FDA limited use to adults without cirrhosis who have been on antivirals for at least six months, have suppressed HBV, and have HBsAg at or below 3,000 IU/mL as measured by an FDA‑authorized Roche diagnostic.
- Safety risks included higher rates of serious adverse events (16% on drug versus 3% on placebo), chiefly raised liver enzymes and thrombocytopenia, so the label carries boxed warnings and requires frequent lab monitoring and careful patient selection.