The approval means that the product will now be available in all the countries of the European Union as well as the European Economic Area.
The gene therapy was approved in the United States in November 2022. It was launched with a price tag of $3.5 million, making it the most expensive treatment to date.
The treatment comprises a one-time infusion of a functional gene that acts as a blueprint for coagulation factor IX, a protein important for blood clotting, stated the manufacturer, CSL.
People living with hemophilia B currently require lifelong treatment of intravenous infusions of factor IX to maintain sufficient levels, which can have a significant impact on their quality of life and well-being, the company explained in its press release.
The approval was based on findings from the pivotal HOPE-B trial, a single-arm, open-label study of 54 men who relied on factor IX replacement therapy; first results from this trial were reported at the 2020 annual meeting of the American Society of Hematology.
The results showed that patients with hemophilia B treated with the gene therapy demonstrated stable and durable increases in mean factor IX activity (with a mean factor IX activity of 36.9%), which led to an adjusted annualized bleeding rate reduction of 64%.
After receiving the gene therapy, 96% of patients discontinued routine factor IX prophylaxis and mean factor IX consumption was reduced by 97% at 18 months post treatment compared with the lead-in period, the company noted.
“Data from the HOPE-B study demonstrate the potential of Hemgenix to remove the need for routine prophylaxis by providing durable factor IX activity, as well as improved bleeding outcomes and quality of life for people with hemophilia B,” said one of the trialists, Wolfgang Miesbach, MD, PHD, head of coagulation disorders at the Comprehensive Care Center, University Hospital of Frankfurt, Germany.
This European approval “marks an important step forward in the treatment of hemophilia B, which could be transformative for people who are debilitated by bleeds into their muscles, joints, and internal organs, alleviating the burden of lifelong intravenous infusions of factor IX products,” Dr. Miesbach said in the company press release.
A version of this article first appeared on Medscape.com.