GSK's Bepirovirsen Meets Phase III Functional Cure Goal for Hepatitis B

GSK said its investigational drug Bepirovirsen achieved a functional cure endpoint in a pivotal Phase III trial for chronic hepatitis B, the company announced on May 28, 2026, marking a significant milestone in the effort to provide a finite treatment for the viral liver disease. The trial met its primary endpoint of sustained hepatitis B surface antigen (HBsAg) clearance after a limited course of therapy, a state considered a functional cure. While detailed efficacy and safety data were not immediately disclosed, the positive readout positions GSK to potentially seek regulatory approval. Chronic hepatitis B affects an estimated 257 million people worldwide, representing a multi-billion-dollar market. GSK shares (NYSE: GSK) rose in pre-market trading following the announcement.