A breakthrough in the race to cure hepatitis B has emerged from a global phase III clinical trial, with a new drug achieving a clinical cure rate of 19 percent in the overall study population. For patients with lower viral activity, that rate climbed to 26 percent, compared with zero percent for those receiving only standard treatment. The results, presented at the European Association for the Study of the Liver meeting in Barcelona, mark a decisive step toward what researchers call the holy grail of hepatitis B treatment.
The drug at the center of this progress is bepirovirsen, an antisense oligonucleotide developed by GSK. It works by targeting the virus directly: its base sequence is complementary to hepatitis B virus RNA, allowing it to form a double-stranded structure with the viral messenger RNA and trigger its degradation. This process inhibits viral DNA replication and reduces levels of hepatitis B surface antigen, or HBsAg, which is a key obstacle to cure. By lowering HBsAg, the drug creates a window for the immune system to recover and mount a sustained response. The B-Well 1 and B-Well 2 trials both met their primary endpoints, and a marketing application has been submitted in multiple countries, including China and the United States.
The stakes are enormous. Hepatitis B is the most prevalent chronic viral disease globally, affecting over 240 million people. In China alone, an estimated 75 million people carry the virus, and more than 450,000 hepatitis B-related deaths occur each year. The virus is particularly difficult to eradicate because it can integrate its DNA into the host genome and form covalently closed circular DNA, or cccDNA, inside liver cells. These forms persist for years and are resistant to existing treatments. Current nucleoside analogs block viral DNA replication but do not clear HBsAg or cccDNA, while long-acting interferon can achieve cure in some patients but has limited effectiveness and significant side effects.
Multiple Approaches and a Combined Future
Beyond bepirovirsen, more than 40 research pipelines are pursuing a hepatitis B cure worldwide. Chinese companies including Haobo Pharmaceutical, Tengshengbo Pharmaceutical, and Hengrui Pharmaceutical have reported new progress. The clinical cure is defined as undetectable HBV DNA and HBsAg in the blood for at least six months after stopping all treatment. Achieving this would not only end the need for lifelong medication but also dramatically reduce the risk of liver cancer and cirrhosis, which are caused by hepatitis B in 80 percent and 60 percent of cases in China, respectively.
Researchers are exploring two main strategies: targeting the virus life cycle with drugs such as entry inhibitors, cccDNA inhibitors, and capsid inhibitors, and awakening the immune system with therapeutic vaccines and immune checkpoint inhibitors. Because cure requires both viral clearance and lasting immune control, combination therapy is expected to be essential. Trials combining new drugs with pegylated interferon are already showing promise in further reducing HBsAg levels and maintaining efficacy.
With bepirovirsen potentially reaching the market as early as 2027 and multiple other candidates advancing, the long-distance race toward a hepatitis B cure is entering its decisive phase. For the millions of patients who have lived with the virus and the risk of liver cancer for decades, the finish line is finally in sight.