uniQure’s Phase 2b trial shows positive response in Hemophilia B patientsPublished: February 8, 2019
Amsterdam-based gene therapy company uniQure has announced 12-week clinical data of its AAV5-based gene therapy trial for treating patients with severe and moderately severe hemophilia B, a rare genetic bleeding disorder.
The ongoing Phase 2b clinical trial is designed to determine the safety and kinetics of a single intravenous infusion of AMT-061 in Hemophilia B patients. AMT-061 is a recombinant AAV5 vector carrying a patent-protected Padua variant of Factor IX (FIX-Padua).
3 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. Data presented at the Annual Congress of the European Association for Haemophilia and Allied Disorders showed increased FIX activity levels in all the patients up to sixteen weeks after gene therapy.
Mean FIX activity for the three patients at twelve weeks increased to 38% (ranging from 25% to 51%) of normal, exceeding threshold FIX levels generally considered enough to eliminate or significantly reduce the risk of bleeding events. The level was also higher than at the 6-week study point. No patient experienced any bleeding event and no serious adverse events were reported.
uniQure had previously used the wild-type FIX for gene therapy, however following the lower effect observed with wild-type FIX, it had reached an agreement with FDA to switch the transgene from wild-type FIX to FIX-Padua, which gives rise to much higher levels of expression of factor IX protein. The result also matches with Spark’s SPK-9001 gene therapy (FIX values ranging from 38% to 54.5%) now being tested for treating hemophilia B.
Patients will be followed for 52 weeks to assess FIX activity and bleeding rates and will be monitored for five years to evaluate the safety of AMT-061.
AMT-061 received FDA’s Breakthrough Therapy Designation and EMA’s access to the Priority Medicine regulatory initiative. Following the news, shares in uniQure rose 5% in premarket trading. The stock is up around 50% since the publication of the 6-week data on AMT-061.
Source: UniQure’s hemophilia B gene therapy clears another clinical test; Press Release