GSK Submits Prospectus for Bepirovirsen (GSK3228836), a Breakthrough Therapy Candidate for Chronic Hepatitis B

On August 9, the official website of the Center for Drug Evaluation (CDE) indicated that GSK's Class 1 new drug, GSK3228836 injection, is proposed for inclusion in the Breakthrough Therapy Designation list, intended for the treatment of chronic hepatitis B. GSK3228836 is an antisense oligonucleotide (ASO) therapy, which GSK believes holds the potential for a "functional cure" of chronic hepatitis B. Currently, the product is undergoing Phase 2 clinical trials globally.

GSK3228836 (also known as GSK'836) is co-developed by GSK and Ionis Pharmaceuticals. By binding to hepatitis B virus (HBV) RNA, it can halt the production of new viral particles and proteins that promote immune tolerance. According to reports, the product utilizes ligand-conjugated antisense technology, which enhances targeted tissue delivery by attaching specific chemical structures or molecules to the candidate drug, thereby making it more efficient and specific in inhibiting HBV replication and expression. Additionally, GSK3228836 can reduce the expression of viral proteins associated with HBV infection and replication, such as the hepatitis B surface antigen (HBsAg), which is expressed in both acute/chronic hepatitis B.

Previously, GSK3228836 demonstrated positive results in a Phase 2a clinical study for the treatment of chronic hepatitis B. The findings indicated that among patients receiving a 300 mg dose of GSK3228836, hepatitis B surface antigen (HBsAg) levels were reduced regardless of prior nucleos(t)ide analogue (NA) treatment status. A total of four patients achieved HBsAg levels below the limit of detection at the end of the 4-week treatment course. Additionally, sustained reductions in HBsAg levels were observed in one NA-naïve patient and one NA-experienced patient, with follow-up extending up to 126 days post-treatment.