New treatment may allow some patients to maintain viral control after stopping all hepatitis B therapy
The U.S. Food and Drug Administration today 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.
“For many people living with chronic hepatitis B, treatment can mean taking antiviral medication for years to keep the virus suppressed,” said Wendy Carter, DO, Acting Director of the Office of Infectious Diseases in the Center for Drug Evaluation and Research. “Hibsago provides a new treatment approach that gives some patients the possibility of maintaining control of the virus after all chronic HBV treatment has ended. This approval represents an important advance for people living with this serious disease.”
Chronic hepatitis B is a long-term liver infection caused by HBV. Over time, the infection can lead to serious liver disease, including cirrhosis, and increase the risk of liver cancer. Hibsago works by targeting the genetic instructions the virus uses to make copies of itself and viral proteins, helping reduce the amount of virus and hepatitis B surface antigen in the body.
The FDA also 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, an inactive treatment. Hibsago is injected under the skin for up to 24 weeks. Patients take it alongside their existing hepatitis B medicine and continue that medicine for at least 24 weeks after their last Hibsago injection. Some patients may then be able to stop their existing medicine if they meet certain health and lab test requirements.
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 a protein that signals hepatitis B infection (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. Hibsago also has warnings for worsening kidney function, serious inflammatory adverse reactions like vasculitis, and serious risks if the injection is not administered properly. Patients need regular blood tests and follow up with their healthcare provider before and during treatment to monitor these risks. The most common side effects, excluding laboratory abnormalities, are injection site reactions, fever, fatigue and headache.
The FDA granted Hibsago Fast Track and Breakthrough Therapy designations as well as Priority Review. The approval was granted to GSK plc.
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