GSK's new hepatitis B drug in China is expected to be included in priority reviews and may achieve functional cure of hepatitis B.

On March 17, the official website of the China National Medical Products Administration (CDE) announced that GlaxoSmithKline plc Sponsored ADR (GSK.US) has filed for priority review for Bepirovirsen solution for injection. This product is intended for a limited course of treatment for chronic hepatitis B virus (HBV) infected individuals, specifically for adults with chronic HBV infection who have nucleos(t)ide analogues in treatment, HBsAg 3000IU/mL, and no liver cirrhosis. This drug has previously been granted breakthrough therapy designation in China, and the decision to grant priority review means that this antisense oligonucleotide therapy, the world's first potentially achieving a functional cure for hepatitis B, is one step closer to Chinese patients. Public information reveals that Bepirovirsen is an antisense oligonucleotide (ASO) therapy under development through collaboration between GSK and Ionis Pharmaceuticals. If approved, Bepirovirsen will be the world's first antiviral therapy requiring only a 6-month limited course of treatment to achieve a functional cure for hepatitis B. GSK plans to officially start the global regulatory approval process in the first quarter of 2026, and the drug has already been submitted for marketing approval in Japan. Bepirovirsen is an investigational ASO therapy with a triple-action mechanism designed to identify and destroy the genetic components (RNA) of the hepatitis B virus, potentially allowing the patient's immune system to regain control of the virus infection. Bepirovirsen can inhibit viral DNA replication in the body, reduce HBsAg levels in the blood, and activate the immune system, increasing the chance of achieving a sustained response. GSK has been granted authorization for Bepirovirsen from Ionis Pharmaceuticals and is collaborating to advance the development of this drug. In January 2026, GSK announced that Bepirovirsen achieved positive results in two key Phase 3 clinical trials for the treatment of chronic hepatitis B, called B-Well 1 and B-Well 2. Both trials met the primary endpoints, showing statistically and clinically significant rates of functional cure with Bepirovirsen. B-Well 1 and B-Well 2 are global, multicenter, randomized, double-blind, placebo-controlled trials designed to evaluate the efficacy, safety, pharmacokinetics, and durability of functional cure of Bepirovirsen in chronic hepatitis B patients receiving nucleos(t)ide analogues therapy with baseline HBsAg 3000 IU/ml. The primary endpoint is the proportion of patients with baseline HBsAg 3000 IU/ml who achieve functional cure. A key secondary endpoint is the proportion of patients with baseline HBsAg 1000 IU/ml who achieve functional cure. Functional cure is defined as loss of HBsAg and undetectable HBV DNA for at least 24 weeks after completion of limited course of treatment. Analyses show that the B-Well trials met the primary endpoint, demonstrating statistically and clinically significant rates of functional cure with Bepirovirsen. Compared to standard treatment alone, Bepirovirsen in combination with standard treatment significantly improved the rate of functional cure. All endpoints reached statistical significance, including patients with baseline HBsAg 1000 IU/ml, showing stronger effects in this group. The trials also demonstrated good safety and tolerability of Bepirovirsen, consistent with previous study results.