FDA Approves First-in-Class Chronic Hepatitis B Drug Hibsago: GSK's Bepirovirsen Shows 19% Functional Cure Rate in Six-Month Course
The U.S. Food and Drug Administration (FDA) on October 20 approved GSK's Hibsago (bepirovirsen) for the treatment of chronic hepatitis B, the first antisense oligonucleotide approved by the FDA for the condition. The drug is to be used in combination with nucleos(t)ide analogue reverse transcriptase inhibitor therapy in adults without cirrhosis who have received that therapy for at least six months, have suppressed HBV DNA, and have hepatitis B surface antigen (HBsAg) levels of no more than 3,000 IU/ml. The approval was granted under the FDA's Priority Review program with Breakthrough Therapy Designation.
Pooled data from the B-WELL phase III trials showed a functional cure rate of 19 percent after a six-month course of bepirovirsen (233 of 1,220 participants), compared with zero in the placebo group; current standard of care typically achieves a functional cure rate of less than 1 percent after one year of treatment. A functional cure means HBV DNA and HBsAg remain undetectable for at least 24 weeks after all treatment stops, indicating the disease is controlled by the immune system without medication. Tony Wood, GSK's Chief Scientific Officer, said many people living with chronic hepatitis B remain on treatment indefinitely and continue to face the risk of serious liver complications, and that Hibsago gives U.S. patients, for the first time, the potential to achieve functional cure after a six-month course, with the option of self-administration after the first dose.
GSK said chronic hepatitis B affects approximately 1.7 million people in the United States, while more than 240 million people worldwide live with the disease and about 1.1 million die from it each year. Bepirovirsen was licensed from Ionis Pharmaceuticals and developed in collaboration with the company; it has already been approved in Japan, and regulatory reviews are under way in China and Europe. The FDA noted that the drug carries a boxed warning for serious liver reactions and thrombocytopenia, and that common adverse reactions include injection site reactions, fever, fatigue and headache, with regular blood testing and clinical follow-up advised before and during treatment.
Published by GSM · USA (original Chinese edition)
Photo: 乙型肝炎病毒（Dane 颗粒）透射电子显微镜图像（资料图）。美国疾病控制与预防中心（CDC）发布，公共领域，经 Wikimedia Commons 发布／Transmission electron micrograph of hepatitis B virions (Dane particles) (file photo). U.S. Centers for Disease Control and Prevention, public domain, via Wikimedia Commons
