FDA Approves Hibsago, the First Antisense Treatment for Chronic Hepatitis B
Used alongside existing antivirals, the injection let nearly one in five trial participants keep the virus under control after stopping all hepatitis B medicine.
Photo: CDC/Dr. Erskine Palmer / Public domain via Wikimedia Commons
The U.S. Food and Drug Administration announced on October 20 that it has approved Hibsago (bepirovirsen), the first antisense oligonucleotide medicine approved for chronic hepatitis B. It is given together with existing antiviral therapy, and for some people it opens a door that current treatments rarely do: the chance to stop all hepatitis B medicine and keep the virus under control.
"Hibsago provides a new treatment approach." — Wendy Carter, DO, FDA Center for Drug Evaluation and Research
Who it is for
The approval covers certain adults without cirrhosis who have taken hepatitis B antiviral therapy for at least six months, have suppressed virus levels, and have hepatitis B surface antigen (HBsAg) levels of 3,000 IU/mL or less. The FDA also authorized a Roche blood test to help select and monitor patients.
What the trials showed
Two placebo-controlled clinical trials supported the decision:
- 24% of people given Hibsago met the requirements to stop their existing medicine, compared with none on placebo.
- 19% still had the virus under control, with HBsAg undetectable, 24 weeks after stopping all hepatitis B treatment.
Hibsago is injected under the skin for up to 24 weeks, with the existing antiviral continued for at least 24 weeks after the last dose. GSK, which developed the drug with Ionis, had said the FDA's target decision date was October 26, so the approval arrived ahead of schedule.
Important cautions
The label carries a boxed warning for serious liver reactions and low platelet counts, which can raise bleeding risk, and patients need regular blood tests. The most common side effects were injection-site reactions, fever, fatigue and headache. Most people in the trials did not reach the stop-treatment goal, so this is a new option for a subset of patients rather than a cure for everyone.
Why it matters
Chronic hepatitis B affects hundreds of millions of people worldwide, and today's antivirals usually have to be taken for life. A first-of-its-kind approach that can sometimes lead to treatment-free control is a meaningful step for patients and the doctors who care for them.
