UniQure recently announced initial clinical data from patients treated in an open-label phase IIb dose-confirmation study of AMT-061, the company’s investigational gene therapy treatment for patients with severe and moderately severe hemophilia B.

The study is a single-arm, single-dose trial of three patients receiving a single intravenous infusion of AMT-061 and evaluated over a period of six to eight weeks to assess their factor IX (FIX) activity. The objective of the study is to assess 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 then 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.

AMT-061 consists of adeno-associated virus serotype 5 (AAV5), which has been demonstrated to be safe and well-tolerated, acting as a delivery vector carrying a gene cassette with the Padua variant of Factor IX. This variant of FIX has been reported to provide an approximate 8 to 9-fold increase in factor activity compared to the wild-type FIX protein employed in another uniQure investigational FIX gene therapy, AMT-060.

In a recent press release the company highlighted data showing that therapeutic levels of FIX activity have been achieved and sustained in all three patients at six weeks after a single administration of the investigational therapy. The mean FIX levels for the three patients was 31% of normal, which is considered sufficient enough to significantly reduce bleeding events. The first patient achieved FIX activity of 37% at ten weeks after administration, the second patient was 23% at eight weeks after administration and the third patient was 30% at six weeks after administration.

“The initial data from our Phase IIb study suggest this target profile is achievable, and we look forward to providing further clinical updates on the study at medical conferences in 2019,” Matt Kapusta, chief executive officer of uniQure.  

Source: uniQure press release dated November 19, 2019