Uniqure NV, of Amsterdam, said AMT-060, its gene therapy for patients with severe hemophilia B, has received PRIME designation by the EMA, based on results from the ongoing, dose-ranging phase I/II study that show a near cessation of spontaneous bleeding in patients with severe disease at up to 12 months follow-up, along with clinically significant and sustained increases in factor IX (FIX) and substantial reductions in FIX replacement usage.