uniQure Presents Updated Clinical Data on Gene Therapy for Hemophilia B

The following is an excerpt from a press release from uniQure. Read the full press release here.

uniQure announced updated clinical data in patients treated in the company’s ongoing Phase IIb 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 was presented at the Hemostasis & Thrombosis Research Society (HTRS) 2019 Scientific Symposium and show that clinically significant elevations of Factor IX (FIX) activity continue to be sustained in all three patients up to six months after a single administration of AMT-061*. AMT-061 has been granted Breakthrough Therapy Designation by the United States Food and Drug Administration and access to the Priority Medicine (PRIME) regulatory initiative by the European Medicines Agency.

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 (endogenous FIX activity less than one percent) were enrolled in the study and received a single intravenous infusion of 2×10¹³ vc/kg. Prior to the administration of AMT-061, all three patients showed low levels of pre-existing neutralizing antibodies to AAV5 but were not excluded from the trial on that basis. Patients in the Phase IIb 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.

Updated data presented at HTRS show that all three patients have demonstrated increasing and sustained FIX levels after the one-time administration of AMT-061, with two of the three patients now achieving FIX activity in the normal range. Mean FIX activity for the three patients at six months after administration  increased to 47 percent of normal. The first patient achieved FIX activity of 51 percent of normal, the second patient achieved FIX activity of 33 percent of normal, and the third patient achieved FIX activity of 57 percent of normal. The second and third patients had previously screen-failed and were excluded from another gene therapy study due to pre-existing neutralizing antibodies to a different AAV vector. Reported FIX activity was measured using an activated partial thromboplastin time (aPTT) assay performed at a central laboratory.

Read the full press release here.