Japan has become the first country to approve GSK's drug Hibsago (bepirovirsen). This is the world's first authorization to use the medicine as a functional agent against chronic hepatitis B.
Japan's Ministry of Health, Labour and Welfare granted approval for adult patients who have already received therapy with nucleos(t)ide analogues for at least six months and meet certain criteria for viral markers. The drug is an antisense oligonucleotide molecule.
The approval was the first global one for bepirovirsen and the first and only functional medicine for chronic hepatitis B in Japan. Nearly a million people in the country live with this disease, and it leads to approximately four thousand deaths each year.
The process was accelerated by the drug receiving SENKU status, which is granted to innovative agents with the potential to address a serious unmet medical need. The decision is based on the results of the phase III B-Well trials.
In these trials, six months of treatment with bepirovirsen achieved a functional cure in 19% of patients with an HBsAg level of ≤3000 IU/mL. By comparison, standard therapy yields this result in only 1% of cases after a year of treatment.
Functional cure means that hepatitis B virus DNA and the surface antigen HBsAg remain undetectable for at least 24 weeks after stopping all drugs. The patient's immune system controls the infection on its own.
GSK's Chief Scientific Officer Tony Wood noted that people with chronic hepatitis B in Japan now have, for the first time, an approved option for a functional cure. After six months of therapy, patients can be freed from lifelong medication and reduce the risk of long-term liver complications.
How will patients' daily lives change when, instead of constant therapy, there is a chance for a limited course of treatment? GSK plans to submit applications for registration of bepirovirsen in other countries, including the United States, in the coming months.
The drug also stimulates the immune response and reduces the production of viral proteins. In the studies, the most commonly reported effects were redness at the injection site, local pain and a temporary increase in liver enzyme levels.
