Introduction#
GSK plc has announced that the U.S. Food and Drug Administration (FDA) has accepted its New Drug Application for bepirovirsen, a new treatment aimed at adults with chronic hepatitis B. This marks a significant step in the development of therapies for this widespread condition.
Breakthrough Therapy Designation#
The FDA has granted bepirovirsen a Breakthrough Therapy Designation. This designation is given to drugs that show promise in preliminary clinical trials, suggesting they may offer substantial improvements over existing treatments. This follows the Fast Track Designation that bepirovirsen received earlier in February 2024, which helps expedite the development and review process for drugs that address unmet medical needs.
Clinical Trial Results#
The regulatory submission for bepirovirsen is backed by results from two Phase III trials, known as B-Well 1 and B-Well 2. In these studies, bepirovirsen was found to significantly improve functional cure rates when used alongside standard treatment compared to standard treatment alone. A functional cure means that the hepatitis B virus is undetectable in the blood for at least 24 weeks after stopping treatment.
Global Impact and Future Steps#
Chronic hepatitis B is a major global health issue, affecting over 250 million people worldwide, including about 1.7 million in the United States. Current treatments often require lifelong therapy, with functional cure rates hovering around 1%. The FDA has set a goal date of October 26, 2026, for its review decision on bepirovirsen. GSK licensed this drug from Ionis Pharmaceuticals, and it is not yet approved in any country. Data from the B-Well trials will be presented at the European Association for the Study of Liver Congress in 2026.