Scientists Report Major Breakthrough In The Fight Against Hepatitis B
A new experimental hepatitis B treatment has delivered what researchers call a functional cure for a significant proportion of patients, allowing them to stop therapy while keeping the virus under control. The results, announced this week, represent one of the most promising advances in hepatitis B treatment in decades.
In two large international clinical trials, about 20% of patients treated with the drug bepirovirsen achieved sustained viral control after ending all therapy. None of the participants who received placebo injections reached the same outcome, highlighting the potential of the new treatment.
How the Drug Works
Bepirovirsen, developed by GSK in collaboration with Ionis Pharmaceuticals, targets the genetic material of the hepatitis B virus and reduces both viral replication and production of a key viral surface protein. By lowering levels of this protein, the treatment may expose the virus to the immune system and help the body maintain long-term control of the infection.
During the trials, patients continued taking their standard daily antiviral medication while receiving weekly injections of either bepirovirsen or a placebo for six months. Those who maintained undetectable virus levels for another six months after completing the injections were then allowed to stop their daily antiviral treatment as well.
Approximately one in five patients who received bepirovirsen kept the virus at undetectable levels for at least six additional months after stopping all therapy. Researchers and independent experts describe this outcome as a functional cure, meaning the virus remains under control without ongoing treatment, even though small amounts may still persist in the body.
Why the Results Are Important
Chronic hepatitis B affects more than 250 million people worldwide and is responsible for an estimated 1.1 million deaths each year, primarily due to liver cancer and liver failure. Existing treatments can effectively suppress the virus, but most patients must continue taking medication for life because the infection typically returns when treatment is stopped.
One of the biggest challenges in curing hepatitis B is the virus’s ability to hide inside liver cells in stable genetic reservoirs. A treatment capable of producing long-lasting remission after therapy ends could significantly change patient care and reduce the burden on healthcare systems, particularly in countries with limited medical resources.
Researchers caution that bepirovirsen is not yet a universal solution. Only a portion of patients achieved a functional cure, and those who started treatment with lower levels of hepatitis B surface protein appeared more likely to respond. This suggests that careful patient selection and combination therapies may further improve outcomes.
Regulatory Review and Future Research
Bepirovirsen is currently under fast-track review by the U.S. Food and Drug Administration, with a regulatory decision expected in October. Health authorities in Europe, China and Japan are also reviewing the phase 3 trial data and results from earlier studies.
Researchers continue to monitor participants to determine how long the functional cure can be maintained after treatment ends. Early follow-up data from previous trials suggest that many responders remain virus-free for up to three years, although larger studies are needed to confirm these findings.
So far, reported side effects have generally been mild and have included injection-site pain or redness and temporary increases in liver enzyme levels. However, the pivotal trials did not include patients with cirrhosis and several other high-risk groups, meaning additional research is required before the treatment can be broadly recommended for all hepatitis B patients.
Scientists are also investigating whether combining bepirovirsen with other emerging therapies, including therapeutic vaccines and immune-modulating treatments, could increase response rates. If future studies confirm these benefits, bepirovirsen could become a key component of new cure-focused treatment strategies for millions of people living with chronic hepatitis B.
