uniQure N.V. announced that its partner CSL has received conditional marketing authorization (CMA) from the European Commission for HEMGENIX® (etranacogene dezaparvovec), the first and only one-time gene therapy for the treatment of severe and moderately severe hemophilia B. HEMGENIX is approved for the treatment of adults with severe and moderately severe hemophilia B (congenital Factor IX deficiency) in adult patients without a history of Factor IX inhibitors. It is the first approved gene therapy for hemophilia B in the European Union (EU) and European Economic Area (EEA). Hemophilia B is a rare, lifelong bleeding disorder caused by a single gene defect, resulting in insufficient production of factor IX, a protein primarily produced by the liver that helps blood clots form.

Treatments for moderate to severe hemophilia B include prophylactic infusions of factor IX replacement therapy to temporarily replace or supplement low levels of blood-clotting factor and, while these therapies are effective, those with hemophilia B must adhere to strict, lifelong infusion schedules. They may also still experience spontaneous bleeding episodes as well as limited mobility, joint damage or severe pain as a result of the disease. For appropriate patients, HEMGENIX has been shown in clinical trials to allow people living with hemophilia B to produce their own factor IX, which can lower the risk of bleeding.

The European Commission's decision follows the CHMP's positive opinion in December 2022, based on findings from the pivotal HOPE-B trial, the larger gene therapy trial in hemophilia B to date. These findings showed that hemophilia B patients treated with HEMGENIX demonstrated stable and durable increases in mean Factor IX activity levels (with a mean Factor IX activity of 36.9%) which led to an adjusted annualized bleed rate (ABR) reduction of 64%. Following infusion, 96% of patients discontinued routine Factor IX prophylaxis and mean Factor IX consumption was reduced by 97% at 18 months post-treatment, compared to the lead-in period.

The HOPE-B study 24-month analysis continued to show a sustained and durable effect of HEMGENIX. In a clinical setting, the treatment is generally well-tolerated with no serious treatment-related adverse events. The multi-year clinical development of HEMGENIX was led by uniQure and sponsorship of the clinical trials transitioned to CSL after it licensed global rights to commercialize the treatment.

In the United Kingdom, The Medicines and Healthcare products Regulatory Agency is currently reviewing CSL's submission for HEMGENIX. HEMGENIX was approved by the U.S. Food and Drug Administration in November 2022. Product information on HEMGENIX, including its prescribing information, will be provided by CSL Behring.