Amid bepirovirsen triumph, GSK quietly scraps trial of next-gen hep B therapy

Biotech Amid bepirovirsen triumph, GSK quietly scraps trial of next-gen hep B therapy By James Waldron Oct 21, 2026 9:35am GSK chronic hepatitis B hepatitis B GSK’s hepatitis B credentials may be secured with Tuesday’s landmark FDA nod for its “functional cure” bepirovirsen, but the pharma has continued to tweak its strategy for next-gen candidates. The drugmaker had been evaluating GSK3965193, a PAPD5/PAPD7 inhibitor, in a phase 1 study that kicked off in 2022. The trial marked the first time GSK3965193 had been tested in humans, with plans to initially test the therapy in healthy participants before exploring how effective the candidate was at lowering hepatitis B virus surface antigen levels in patients with chronic hepatitis B (CHB) infection.

However, GSK updated the federal clinical trials registry to disclose that the company had made the “strategic decision” to end the study. A spokesperson confirmed to Fierce this morning that the study has been terminated. At the time of publication, GSK still listed GSK3965193 on its website as being in phase 1 development, but the company declined to clarify to Fierce whether pulling the plug on the trial marked the end of the road for the candidate.

The confirmation of the trial’s termination comes as GSK clocked a major win for its hepatitis B ambitions with the groundbreaking FDA approval of bepirovirsen on Tuesday. The Ionis-licensed medicine will be marketed by GSK as Hibsago to treat CHB in combination with nucleos(t)ide analogue reverse transcriptase inhibitor therapy in adults without cirrhosis. GSK entered the year with a number of potential follow-ups to bepirovirsen in the works.

But, with the TLR8 agonist GSK5251738 scrapped and GSK3965193’s future in doubt, the one significant candidate still in development appears to be the phase 2-stage hepatitis B virus-targeted siRNA drug GSK5637608. Where Big Pharma is placing its bets is one of the hot topics being discussed at Fierce Biotech's high-impact event in London next month. Find out more information and register by clicking on the banner below: GSK chronic hepatitis B hepatitis B Biotech