FDA Approves First-of-Its-Kind Chronic Hepatitis B Treatment

The U.S. Food and Drug Administration approved Hibsago (bepirovirsen) injection, in combination with existing antiviral therapy, to treat chronic hepatitis B virus (HBV) infection in certain adults without cirrhosis. Hibsago is the first FDA-approved antisense oligonucleotide to treat chronic hepatitis B.

Hibsago is approved for certain adults without cirrhosis who have been taking HBV antiviral therapy for at least six months, have suppressed levels of HBV in their blood and have hepatitis B surface antigen (HBsAg) levels of 3,000 IU/mL or less, as determined by an FDA-authorized test.

The FDA authorized the Roche Elecsys HBsAg II quant II RxDx assay as a companion diagnostic device to aid in the selection of patients with chronic HBV infection for treatment with antiviral therapy in accordance with the FDA approved drug labeling and to assist in monitoring patients throughout the course of treatment.

Researchers studied Hibsago in two clinical trials that compared it with a placebo. Across the two trials, 24% of patients who received Hibsago met the requirements to stop their existing medicine, compared with none who received placebo. Twenty-four weeks after stopping all hepatitis B treatment, 19% of patients who received Hibsago still had the virus under control, and HBsAg could not be detected in their blood.

Hibsago has a boxed warning for serious liver reactions as well as low platelet counts, which can increase the risk of potentially life-threatening bleeding. The most common side effects are injection site reactions, fever, fatigue and headache. The approval was granted to GSK plc.