UniQure’s hemophilia B gene therapy achieves 31% FIX activity

UniQure has posted eagerly-anticipated data on the modified hemophilia B gene therapy it plans to take into phase 3. The FIX-Padua variant therapy achieved factor IX (FIX) activity levels of 23% to 37%, suggesting it is several times more effective than the version uniQure tested in earlier-phase trials. Throughout the development of its earlier, wild-type FIX gene therapy AMT-060, uniQure suffered as a result of unfavorable comparisons to Spark Therapeutics’ rival FIX Padua candidate SPK-9001. While the high dose of AMT-060 triggered FIX activity of 3% to 12.7%, the latest version of Pfizer-partnered SPK-9001 sent levels up to between 38.1% and 54.5%. A patient who received a version of SPK-9001 made under a previous process achieved FIX activity of 76.8%.