FDA approves GSK‑Ionis hepatitis B functional cure, Hibsago, targeting undetectable virus after six months

The FDA has approved bepirovirsen, an antisense oligonucleotide from GSK and Ionis, for chronic hepatitis B infection. It will be sold under the brand name Hibsago.

The therapy is described as a functional cure, capable of reducing viral levels to undetectable after six months of treatment, potentially allowing patients to stop long‑term medication.

GSK projects peak worldwide sales of over £2 billion ($2.67 billion), while BMO Capital Markets estimates a peak of $659 million. Ionis will receive tiered royalties of 10‑12% on GSK sales, roughly $163 million.

Analysts say the approval adds meaningful validation to Ionis’s antisense platform after recent setbacks in the class.