Hemophilia B gene therapy Hemgenix approved in Switzerland
Swissmedic authorized treatment for adult males, ages 18 and older
Hemgenix (etranacogene dezaparvovec), the first and only one-time gene therapy approved for hemophilia B, has been approved in Switzerland, CSL Behring, the company marketing the therapy globally, announced.
“The approval of Hemgenix in Switzerland marks an important milestone for patients, and we look forward to collaborating with the hemophilia B community to provide access to this innovative treatment option,” Isabelle Dahinden, general manager Switzerland at CSL Behring, said in a company press release.
The approval from Swissmedic authorized Hemgenix as a treatment for adult males, ages 18 and older, who have severe or moderately severe hemophilia B.
“We are proud to add this treatment to our portfolio of coagulation therapies and look forward to patients benefiting from this therapy,” Dahinden said.
Emmanuelle Lecomte-Brisset, senior vice president and head of global regulatory affairs at CSL, said the approval “is further demonstration of CSL’s promise to pursue, develop and deliver new innovative treatment options that meet the needs of the rare disease community.”
Hemophilia B is caused by mutations in the F9 gene that provides instructions to make factor IX (FIX), a clotting protein. People with severe or moderately severe hemophilia B have FIX activity levels that are 2% or lower than normal, putting them at an increased risk of excessive and prolonged bleeds.
How does Hemgenix work?
Hemgenix delivers a healthy copy of the gene encoding FIX to cells in the liver, where clotting factor proteins are made. By delivering a working version of this gene to cells, the gene therapy should restore the ability to produce functional FIX, thereby normalizing clotting activity and reducing, or eliminating, the need for FIX replacement therapies.
The gene therapy was approved in the U.S. in late 2022. The next year it was approved in Canada and conditionally authorized in the European Union and the U.K. CSL acquired the global rights to commercialize Hemgenix after entering into a licensing agreement with its original developer, uniQure in 2021.
Like previous approvals, Swissmedic’s approval of Hemgenix was supported mainly by data from the Phase 3 HOPE-B clinical trial (NCT03569891). The study, which is still ongoing, is tracking the outcomes of more than 50 men with severe or moderately severe hemophilia B who received a single dose of the gene therapy.
Top-line trial results showed the gene therapy increased FIX activity levels as designed, with the latest data showing that after three years, FIX activity levels remained increased at 38.6% of normal, on average. FIX activity levels between 5-40% of normal are within the range of mild hemophilia, while activity levels higher than 50% are considered normal for people who don’t have hemophilia.
Findings from HOPE-B have also shown Hemgenix was generally safe and that the gene therapy helped reduce bleed rates and lowered the need for replacement therapies, with 75% of the patients requiring no FIX replacement at all in the third year after treatment.