FDA grants approval for GSK’s Hibsago as the first functional cure for hepatitis B.

The FDA has approved GSK’s Hibsago (bepirovirsen) as a functional cure for chronic hepatitis B (CHB), making it the first antisense oligonucleotide (ASO) therapeutic cleared for the indication. Announced on 20 October 2026, approximately a week ahead of the PDUFA date, the approval follows Japan’s green-light two months earlier and includes authorisation of Roche’s Elecsys HBsAg II quant II RxDx assay as companion diagnostic for eligibility determination.

Hibsago’s label covers adults without cirrhosis who have received at least six months of prior nucleos(t)ide analogue reverse transcriptase inhibitor therapy and have hepatitis B surface antigen (HBsAg) levels of ≤3,000 IU/ml. The FDA decision was driven by Phase III data from the B-Well 1 and B-Well 2 trials, which randomised a combined 1,834 CHB patients to once-weekly Hibsago injection for six months or placebo. Results presented at EASL in May 2026 showed 19% of Hibsago recipients achieved functional cure, defined as undetectable HBV DNA and HBsAg levels for at least 24 weeks post-treatment, characterised as unprecedented in the CHB category.

Hibsago’s approval sharpens competitive positioning across the chronic hepatitis B market, where Gilead Sciences dominates with suppressive nucleos(t)ide analogue therapies Vemlidy and Viread, alongside Bristol Myers Squibb’s Baraclude (entecavir). As the first functional cure, Hibsago repositions the category from indefinite viral suppression toward curative time-limited treatment. Competitors advancing CHB cure approaches include Vir Biotechnology, Assembly Biosciences, Arrowhead Pharmaceuticals/Johnson & Johnson (JNJ-3989) and Replicor. The Elecsys companion diagnostic authorisation strengthens Roche Diagnostics’ positioning against Abbott and Siemens Healthineers Diagnostics.

The commercial signal is a historic category-defining first for chronic hepatitis B, where a time-limited ASO curative therapy challenges three decades of indefinite nucleos(t)ide analogue suppressive maintenance economics. 19% functional cure sets a competitive bar for ASO, siRNA and immunotherapy pipelines. Expect Gilead Sciences, Bristol Myers Squibb, Vir Biotechnology, Assembly Biosciences and Arrowhead Pharmaceuticals/J&J to sharpen CHB positioning through 2027 and 2028.

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