FDA approves GSK/Ionis Hibsago (bepirovirsen) for chronic hepatitis B; Ionis earns 10-12% royalties

IONIS PHARMACEUTICALS INC

• FDA approved Hibsago (bepirovirsen) for CHB in adults without cirrhosis, on NrtI therapy ≥6 months, with suppressed HBV DNA and HBsAg ≤3000 IU/ml.
• Phase 3 B-Well pooled data: 19% functional cure (233 of 1,220) vs 0 of 614 on placebo; 26% (200 of 768) in patients with HBsAg ≤1000 IU/ml.
• Approval granted under FDA priority review and Breakthrough Therapy Designation; bepirovirsen is also approved in Japan, with more global decisions expected.
• Ionis licensed bepirovirsen to GSK in 2019; already received upfront, license fee and milestone payments, and is eligible for more milestones plus 10-12% tiered royalties.
• CHB affects roughly 1.7 million people in the U.S.; label carries boxed warnings for on-treatment hepatic flares and thrombocytopenia.