Japan’s Ministry of Health, Labour and Welfare has granted the first global approval for GSK plc’s Hibsago, a treatment for chronic hepatitis B virus infection in adults. The approval applies to patients who have undergone at least six months of prior nucleos(t)ide analogue therapy and meet specific viral marker criteria.
Hibsago, known generically as bepirovirsen, is an antisense oligonucleotide designed to suppress the production of hepatitis B virus genetic components. GSK licensed the drug from Ionis Pharmaceuticals and co-developed it. The approval follows Phase III B-Well trial data showing functional cure rates of 19% in adults with hepatitis B surface antigen (HBsAg) levels of 3,000 IU/ml or lower, compared with a 1% cure rate from current standard-of-care treatments alone after one year.
In a subgroup with HBsAg levels of 1,000 IU/ml or lower, the functional cure rate reached 26%. This subgroup represents approximately 45% of diagnosed chronic hepatitis B cases globally. The pooled B-Well trial population included 1,220 participants receiving bepirovirsen and 614 in the placebo group. Among those with HBsAg levels of 1,000 IU/ml or lower, 768 participants were enrolled.
Japan’s approval was expedited under the SENKU designation, reserved for innovative therapies addressing high unmet medical need. Nearly 1 million people in Japan live with chronic hepatitis B, which contributes to approximately 4,000 annual deaths, according to regulatory filings.
GSK’s shares closed at 1,918.50 GBP on August 21, down 0.10%. The company has initiated regulatory submissions in additional markets, including the United States, with decisions anticipated in the coming months.
