European Commission Approves First Gene Therapy for Hemophilia B

The European Commission (EC) granted conditional marketing authorization to etranacogene dezaparvovec (Hemgenix, CSL Behring), a one-time gene therapy for the treatment of severe and moderately severe hemophilia B in adults without a history of Factor IX inhibitors.  

Etranacogene dezaparvovec is an adeno-associated virus five (AAV5)-based gene therapy that works by carrying a naturally occurring Padua gene variant of Factor IX (Factor IX-Padua), which generates Factor IX proteins that are 5-8 times more active than normal. It is the first approved gene therapy for hemophilia B in the European Union and European Economic Area.

The EC approved the therapy in response to data from the HOPE-B trial. Findings showed that hemophilia B patients treated with etranacogene dezaparvovec experienced durable increases in mean Factor IX activity levels and reduced annualized bleed rates.

In the United States, the Food and Drug Administration approved etranacogene dezaparvovec last year for hemophilic adults who are currently being treated with Factor IX prophylaxis and have a history of repeated, serious bleeding episodes.