GSK is positioning its first-in-class antisense oligonucleotide bepirovirsen for launch in mainland China through an exclusive commercial collaboration with Chia Tai Tianqing Pharmaceutical Group (CTTQ), a subsidiary of Sino Biopharmaceutical (HKEX: 1177.HK). Under the agreement announced May 11, CTTQ will handle importation, distribution, hospital access, and promotional activities for bepirovirsen in mainland China, while GSK (NYSE: GSK) retains the marketing authorization and full regulatory, quality, and pharmacovigilance responsibilities. Financial terms were not disclosed.
The structure reflects a supply-based commercial model: CTTQ will purchase bepirovirsen from GSK under agreed supply terms and recognize product sales revenue in China. The initial term runs 5.5 years, with extension by mutual agreement. The agreement also includes a provision for both parties to explore future collaboration on Sino Biopharmaceutical's broader R&D pipeline assets outside China, though no formal terms govern that element.
Deal context
Bepirovirsen is an antisense oligonucleotide described by GSK as having a triple mechanism of action: degrading HBV pregenomic RNA and mRNA, suppressing hepatitis B surface antigen (HBsAg) production, and stimulating innate immune responses via Toll-Like Receptor 8. The goal is functional cure — defined as sustained HBsAg loss off treatment — which distinguishes it from existing antiviral therapies that require lifelong use for viral suppression.
The asset holds Breakthrough Therapy designation from both the US FDA and China's National Medical Products Administration (NMPA), along with Fast Track status in the US and Priority Review in Japan. In China, the NMPA's Center for Drug Evaluation accepted bepirovirsen for Priority Review in April 2026, supported by results from the B-Well 1 and B-Well 2 Phase III trials. Phase IIb data from the B-Clear study demonstrated functional cure rates of approximately 9–10% at 24 weeks post-treatment, providing the clinical foundation for the Phase III program.
China represents a substantial market for any hepatitis B therapy. According to WHO data cited in the announcement, approximately 75 million people in China live with chronic hepatitis B, and the condition is associated with roughly 450,000 deaths annually. China's National Action Plan for the Prevention and Treatment of Viral Hepatitis (2025–2030) has identified functional cure as a treatment goal, which aligns directly with bepirovirsen's proposed profile.