FDA approves GSK’s Hibsago for chronic hepatitis B

• GSK (NYSE:GSK) received U.S. regulatory approval for Hibsago (bepirovirsen), the first FDA-approved antisense oligonucleotide treatment for chronic hepatitis B, for a defined group of adults without cirrhosis.
• The B-Well trials demonstrated a 19% functional cure rate, compared with 0% in the placebo group receiving background antiviral treatment. The rate increased to 26% in patients with lower baseline hepatitis B surface antigen levels.
• GSK anticipates annual peak sales exceeding £2 billion, although pricing and launch availability remain undisclosed. Hibsago carries boxed warnings for serious liver reactions and low platelet counts.

GSK (NYSE:GSK) received U.S. Food and Drug Administration approval for Hibsago (bepirovirsen), an RNA-targeted treatment for certain adults with chronic hepatitis B.

The approval covers patients without cirrhosis who have received antiviral therapy for at least six months, have suppressed HBV DNA and qualifying surface antigen levels.

Tony Wood, GSK's chief scientific officer, said Hibsago offers eligible U.S. patients the potential for functional cure following a six-month treatment course.

Pooled Phase III B-Well results showed functional cure in 19% of treated patients, or 233 of 1,220, compared with none of 614 controls.

Among participants with baseline HBsAg levels no higher than 1,000 IU/mL, the functional cure rate reached 26%, versus 0% in controls.

GSK expects Hibsago to generate more than £2 billion in annual peak sales, while continuing regulatory submissions in other markets and developing commercialization plans.

The treatment was licensed from Ionis Pharmaceuticals and is approved in Japan and the U.S., although patients require continued antiviral treatment and monitoring for serious safety risks.