uniQure (QURE) shares have climbed 7% in late afternoon trade Friday as the company shared positive results on an updated clinical data in patients treated in the company’s ongoing phase 2b 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.

According to a statement, the updated data 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 US Food and Drug Administration and access to the priority medicine (PRIME) regulatory initiative by the European Medicines Agency.

The Phase 2b study of AMT-061 is an open-label, single-dose, single-arm, multi-center trial being conducted in the US. Three patients with severe hemophilia (endogenous FIX activity less than 1%) were enrolled in the study and received a single intravenous infusion of 2×1013 vc/kg.

Updated data show 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% of normal. The first patient achieved FIX activity of 51% of normal, the second patient achieved FIX activity of 33% of normal, and the third patient achieved FIX activity of 57% of normal.

The company said none of the patients received factor infusions or reported bleeding events over a combined 78 weeks of observation.