GSK and Ionis Announce Phase 3 Success for Bepirovirsen, Potential Functional Cure for Chronic Hepatitis B
GSK and Ionis reported positive top-line results from the Phase 3 B-Well 1 and B-Well 2 trials of bepirovirsen on January 7, 2026, meeting the primary endpoint with statistically significant and clinically meaningful functional cure rates in chronic hepatitis B patients.126
Functional cure is defined as sustained loss of hepatitis B surface antigen (HBsAg) and undetectable HBV DNA for at least 24 weeks post-treatment, allowing immune control without ongoing medication.236
Bepirovirsen plus standard of care showed higher functional cure rates than standard care alone, especially in patients with baseline HBsAg ≤1000 IU/ml, across all ranked endpoints.146
The trials involved over 1,800 patients from 29 countries, demonstrated acceptable safety and tolerability, and GSK plans global regulatory filings starting Q1 2026.2456
Bepirovirsen, an antisense oligonucleotide licensed from Ionis, could become the first finite six-month treatment for chronic hepatitis B, addressing a disease affecting over 250 million people.456
Sources:
1. https://www.gsk.com/media/rfabtexl/press-release-gsk-announces-positive-results-from-b-well-1-and-b-well-2-phase-iii-trials-for-bepirovirsen-a-potential-first-in-class-treatment-for-chronic-hepatitis-b-1.pdf
2. https://www.biospace.com/drug-development/gsk-ionis-achieve-functional-cure-in-hepatitis-b-studies-clearing-path-for-fda-run
3. https://www.biopharmadive.com/news/gsk-ionis-bepirovirsen-hepatitis-b-drug-results/808967/
4. https://www.fiercebiotech.com/biotech/gsks-functional-cure-hep-b-proves-worth-phase-3-trials-setting-approval-push
5. https://medcitynews.com/2026/01/gsk-chronic-hepatitis-b-functional-cure-liver-infectious-disease-bepirovirsen-ionis-ions/
6. https://www.gsk.com/en-gb/media/press-releases/gsk-announces-positive-results-from-b-well-1-and-b-well-2-phase-iii-trials-for-bepirovirsen-a-potential-first-in-class-treatment-for-chronic-hepatitis-b/