An experimental new treatment for chronic hepatitis B is raising hopes for what researchers call a potential “functional cure,” a milestone that could change how the viral liver disease is managed in the future.
The investigational drug, called bepirovirsen and developed by GSK and Ionis Pharmaceuticals, showed promising results in two international clinical studies involving nearly 1,900 patients with chronic hepatitis B. Researchers found that roughly 20% of treated patients were able to stop therapy while maintaining undetectable levels of the virus for at least six months afterward.
The findings were presented at a scientific meeting in Barcelona and simultaneously published in the New England Journal of Medicine.
Chronic hepatitis B is a potentially life-threatening infection spread through contact with infected blood or bodily fluids, including during childbirth. The disease can quietly damage the liver over time, increasing the risk of cirrhosis, liver failure, and liver cancer. Global estimates suggest hepatitis B contributes to about 1 million deaths annually.
Although existing antiviral medications can suppress the virus and reduce liver damage, they rarely eliminate the infection completely because hepatitis B can remain dormant in the body and reactivate after treatment ends.
Researchers said bepirovirsen works differently from current therapies by targeting the virus’s genetic material while reducing levels of hepatitis B surface antigen, a protein that helps the virus persist inside the body. The therapy may also help stimulate immune responses against infected liver cells.
In the trials, participants received weekly injections of bepirovirsen for six months while continuing standard antiviral medications. Patients who maintained undetectable viral levels afterward were later able to discontinue their routine therapy. Researchers reported that no patients in the placebo groups achieved the same sustained response.
Investigators described the findings as one of the strongest signs so far that long-term, treatment-free viral control may be achievable for at least some patients with chronic hepatitis B.
However, they cautioned that most participants did not achieve a functional cure, and researchers are still trying to determine why certain patients responded better than others.
Independent experts called the results a significant step forward in hepatitis B research, though they noted that longer follow-up will be necessary to determine how durable the response remains over time.
Regulatory agencies in the United States, Europe, Japan, and China are currently reviewing the therapy. Bepirovirsen has also received fast-track designation from the U.S. Food and Drug Administration, fueling optimism that hepatitis B treatment may eventually move beyond lifelong viral suppression and closer toward functional cure strategies.
