uniQure Announces Initial Topline Data

uniQure, a leading gene therapy company advancing transformative therapies for patients with severe unmet medical needs, today announced initial clinical data in patients treated in the Company’s Phase IIb dose-confirmation study of AMT-061, an investigational AAV5-based gene therapy containing a patent-protected FIX-Padua variant, for the treatment of patients with severe and moderately severe hemophilia B. These data show that therapeutic levels of Factor IX (FIX) activity have been achieved and sustained in all three patients at six weeks after a single administration of AMT-061.* AMT-061 has been granted Breakthrough Therapy Designation by the United States Food and Drug Administration (FDA) and access to the Priority Medicine (PRIME) regulatory initiative by the European Medicines Agency (EMA).

The Phase IIb study of AMT-061 is an open-label, single-dose, single-arm, multi-center trial being conducted in the United States. Three patients with severe hemophilia were enrolled in this study and received a single intravenous infusion of 2×1013 vc/kg. Patients are evaluated for the presence of pre-existing neutralizing antibodies to AAV5 but not excluded from the trial on that basis. The objective of the study is to evaluate the safety and tolerability of AMT-061 and confirm the dose based on FIX activity at six weeks after administration. Patients in the study will be followed for 52 weeks to assess FIX activity, bleeding rates and usage of FIX replacement therapy, and will be monitored for five years to evaluate the safety of AMT-061.

Data from the study show that all three patients experienced increasing and sustained FIX levels after a one-time administration of AMT-061. Six weeks after administration mean FIX activity for the three patients was 31% of normal, exceeding threshold FIX levels generally considered sufficient to significantly reduce the risk of bleeding events. FIX activity was measured using an activated partial thromboplastin time (aPTT) assay performed at a central laboratory. The first patient achieved FIX activity of 37% of normal at ten weeks after administration. FIX activity in the second patient was 23% of normal at eight weeks following administration and in the third patient was 30% of normal at six weeks after administration. The second and third patients had previously screen-failed another gene therapy study due to pre-existing neutralizing antibodies to a different AAV vector.

Source: Forbion (press release)