uniQure and CSL Behring announce primary endpoint achieved in HOPE-B pivotal trial of etranacogene dezaparvovec gene therapy in patients with hemophilia B.

The study also successfully achieved a secondary endpoint demonstrating statistical superiority in reduction of ABR compared to baseline FIX prophylactic therapy. The primary endpoint in the pivotal study was 52-week ABR after achievement of stable FIX expression compared with the six-month lead-in period, considering all bleeds regardless of investigator adjudication as true bleeds. For this endpoint, ABR was measured from month seven to month 18 after infusion, ensuring the observation period represented likely steady-state FIX transgene expression. Secondary endpoints included assessment of FIX activity and statistical superiority of ABR after dosing.

Top-line Data Results : A total of 54 patients received a single dose of etranacogene dezaparvovec in the pivotal trial, with 53 patients completing at least 18 months of follow-up. ABR for all bleeds after stable FIX expression, assessed at 18 months, was 1.51 compared with the ABR of 4.19 for the lead-in period of at least six months, achieving the primary non-inferiority endpoint and a secondary superiority endpoint (p=0.0002) in the HOPE-B trial. ABR for investigator-adjudicated FIX-treated bleeds was 0.83 compared with lead-in ABR of 3.65 (p<0.0001). data from the hope-b pivotal trial showed that patients continued to demonstrate durable, sustained increases in fix activity at 18 months post-infusion with a mean fix activity of 36.9 percent of normal as measured by a one-stage aptt-based clotting assay, compared to mean fix activity of 39.0 percent of normal at six months post-infusion.></0.0001).>

Etranacogene dezaparvovec has been granted Breakthrough Therapy Designation by the FDA and access to Priority Medicine (PRIME) regulatory initiative by the European Medicines Agency. CSL Behring plans to submit regulatory applications for marketing approval of etranacogene dezaparvovec in the United States and European Union in the first half of 2022.