GSK's Hibsago (bepirovirsen) approved in US for chronic hepatitis B
- FDA approved Hibsago (bepirovirsen) for adults without cirrhosis on NrtI therapy ≥6 months with suppressed HBV DNA and baseline HBsAg ≤3000 IU/ml.
- Pooled B‑Well phase III data showed a 19% functional cure rate (233 of 1,220) versus 0 of 614 with placebo in the ≤3000 IU/ml population.
- In the ≤1000 IU/ml subgroup, functional cure was 26% (200 of 768) versus 0 of 393 with placebo.
- Treatment is six months with option of self‑administration after the first dose; HBsAg ≤100 IU/ml was achieved in 49% overall and 62% of the ≤1000 subgroup at week 72.
Regulatory approval and indication
GSK announced FDA approval of Hibsago (bepirovirsen) for treatment of chronic hepatitis B in adults without cirrhosis who have been on nucleos(t)ide analogue reverse transcriptase inhibitor therapy for at least six months, have suppressed HBV DNA, and baseline HBsAg ≤3000 IU/ml. The approval was granted under priority review and Breakthrough Therapy Designation.
Phase III efficacy
Pooled B‑Well trials reported a 19% functional cure rate after six months of bepirovirsen (233 of 1,220) versus 0 of 614 with placebo in the ≤3000 IU/ml population. A key secondary endpoint showed 26% functional cure (200 of 768) in participants with ≤1000 IU/ml HBsAg. Functional cure is defined as undetectable HBV DNA and HBsAg for at least 24 weeks after stopping all treatment.
Virologic responses and testing
Exploratory analyses found HBsAg ≤100 IU/ml in 49% of participants overall and 62% of the ≤1000 IU/ml subgroup at week 72. Quantitative surface antigen testing will support diagnosis and patient selection, and several FDA‑authorised tests are available.
Safety
Trials reported an acceptable safety and tolerability profile; the most frequent adverse events were injection‑site erythema, local pain and temporary rises in a liver enzyme.
Source: GSK