GSK Advances Hepatitis B Treatment Pipeline with China NDA Submission for Bepirovirsen Based on Phase III Trial Success

GSK Advances Hepatitis B Treatment Pipeline with China NDA Submission for Bepirovirsen Based on Phase III Trial Success

(IN BRIEF) GSK has announced that China’s National Medical Products Administration has accepted for review a New Drug Application for bepirovirsen, an investigational antisense oligonucleotide designed to treat adults with chronic hepatitis B. The submission is supported by Phase III B-Well trial data showing statistically significant and clinically meaningful improvements in functional cure rates compared with standard therapies. Chronic hepatitis B remains a major health burden globally and in China, where millions are affected and hundreds of thousands of deaths occur annually. Current treatments often require lifelong use and rarely achieve functional cure, highlighting the need for new therapeutic approaches. Bepirovirsen has also received Breakthrough Therapy designation in China, reflecting its potential to significantly improve treatment outcomes if approved.

(PRESS RELEASE) LONDON, 30-Mar-2026 — /EuropaWire/ — GSK plc has announced that the National Medical Products Administration has accepted for review a New Drug Application (NDA) for bepirovirsen, an investigational antisense oligonucleotide (ASO) therapy intended for the treatment of adults living with chronic hepatitis B (CHB).

Chronic hepatitis B remains a critical global health concern, impacting more than 250 million individuals worldwide, including an estimated 75 million people in China. Despite existing treatment options such as nucleos(t)ide analogues, many patients require lifelong therapy, and the likelihood of achieving a functional cure remains very low—typically around 1%. A functional cure is defined by the sustained absence of hepatitis B virus DNA and hepatitis B surface antigen (HBsAg) in the bloodstream for at least 24 weeks after discontinuing treatment, indicating that the immune system can control the infection without ongoing medication. Achieving this outcome is associated with a substantial reduction in the risk of long-term complications, including liver cancer. In China alone, chronic hepatitis B contributes to approximately 450,000 deaths each year.

The submission to the NMPA is supported by data from the Phase III B-Well 1 and B-Well 2 clinical trials. In these pivotal studies, bepirovirsen demonstrated statistically significant and clinically meaningful improvements in functional cure rates compared with standard of care alone. The therapy showed consistent benefits across all evaluated endpoints, with particularly strong results observed in patients who had lower baseline levels of HBsAg.

Bepirovirsen was also found to have a safety and tolerability profile that aligns with findings from earlier clinical studies. Full results from the B-Well trials are expected to be presented at a scientific congress and submitted for peer-reviewed publication in 2026.

The investigational therapy previously received Breakthrough Therapy designation in China in August 2021, a status granted to treatments that demonstrate the potential to offer significant advantages over existing therapeutic options and to accelerate regulatory review timelines.

Clinical trial programme

B-Well 1 [NCT05630807] and B-Well 2 [NCT 05630820] trials are global multi-centre, randomised, double-blind, placebo-controlled trials conducted in 29 countries. They assessed the efficacy, safety, pharmacokinetic profile, and the durability of functional cure in nucleos(t)ide analogue (NA)-treated in non-cirrhotic participants with CHB and baseline surface antigen (HBsAg) ≤3000 IU/ml. The primary endpoint assessed the proportion of participants achieving functional cure in patients with baseline surface antigen (HBsAg) ≤3000 IU/ml. A key ranked secondary endpoint evaluated functional cure in patients with baseline HBsAg ≤1000 IU/ml.

About chronic hepatitis B

Hepatitis B is a viral infection that can cause both acute and chronic liver disease. Chronic hepatitis B occurs when the immune system is unable to clear the virus, resulting in long-lasting infection. CHB affects more than 250 million people worldwide. Each year, the disease causes approximately 1.1 million deaths, and approximately 450,000 deaths in China.¹ Many patients often require lifelong antiviral therapy for viral suppression; making functional cure a critical goal in disease management.

About bepirovirsen

Bepirovirsen is a triple action investigational antisense oligonucleotide (ASO), designed to recognise and orchestrate the destruction of the genetic components (i.e. mRNA and pregenomic RNA) of the hepatitis B virus that can lead to chronic disease, potentially allowing a person’s immune system to regain control. Bepirovirsen inhibits the replication of the viral genome in the body, suppresses the level of hepatitis B surface antigen (HBsAg) in the blood, and stimulates the immune system to increase the chances of a durable and sustained response.

Bepirovirsen is also being evaluated as a potential backbone therapy for future sequential treatment strategies aimed at expanding functional cure to broader patient populations.

GSK licensed bepirovirsen from Ionis Pharmaceuticals and collaborated with them on its development. Bepirovirsen has been recognised by global regulatory authorities for its innovation and potential to address significant unmet need in hepatitis B, with Fast Track designation from the US FDA, Breakthrough Therapy designation in China and SENKU designation in Japan. Bepirovirsen is currently not approved anywhere in the world.

About GSK

GSK is a global biopharma company with a purpose to unite science, technology, and talent to get ahead of disease together. Find out more at www.gsk.com.

Cautionary statement regarding forward-looking statements

GSK cautions investors that any forward-looking statements or projections made by GSK, including those made in this announcement, are subject to risks and uncertainties that may cause actual results to differ materially from those projected. Such factors include, but are not limited to, those described in the “Risk Factors” section in GSK’s Annual Report on Form 20-F for 2025.

References

1. WHO Global Hepatitis Report 2024. Available at https://www.who.int/publications/i/item/9789240091672 (last accessed March 2026)
2. Rumgay H et al . Global burden of primary liver cancer in 2020 and predictions to 2040. J Hepatol. 2022;77:1598–1606. doi: 10.1016/j.jhep.2022.08.021
3. Slaets, L. et al. “Systematic review with meta-analysis: hepatitis B surface antigen decline and seroclearance in chronic hepatitis B patients on nucleos(t)ide analogues or pegylated interferon therapy” in GastroHep 2, 106–116 (2020)
4. EASL, “Clinical Practice Guidelines on the management of hepatitis B virus infection” in Journal of Hepatology Volume 83, Issue 2, August 2025, Pages 502-583. Available at: https://www.sciencedirect.com/science/article/pii/S0168827825001746 (last accessed: January 2026)

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SOURCE: GlaxoSmithKline plc