uniQure N.V. has updated the clinical data from its ongoing clinical trial of a gene therapy for the treatment of patients with hemophilia B. The results indicate sustained improvement by all patients at a low-dose, with durable levels of Factor IX (FIX) gene activity for several weeks after treatment.
The updated data was presented recently at the World Federation of Hemophilia (WFH) 2016 World Congress, in Orlando, Florida. The company also presented results from the Phase 1/2 clinical trial of AMT-060 at the 21st Congress of the European Hematology Association (EHA), in Copenhagen.
Titled “Trial of AAV5-hFIX in Severe or Moderately Severe Hemophilia B,” the trial included 10 patients with documented severe or moderately-severe hemophilia B, who each received a one-time intravenous treatment of AMT-060. The patients were divided into two dose groups, five in each, one receiving 5×1012 gc/kg and the other receiving 2×1013 gc/kg.
The AMT-060 gene therapy, co-developed with Chiesi for Europe, comprises a codon-optimized wild type FIX gene cassette, the LP1 liver promoter, and an AAV5 viral vector manufactured through the company’s proprietary insect cell-based technology platform.
Key results, which refer to the low-dose cohort, indicate that four patients discontinued prophylactic FIX infusions and that their FIX activity was 5.4% of normal, with a range from 3.1% to 6.7% of normal. Such results indicate a substantial reduction in the need for FIX replacement therapy for hemophilia patients.
For all five patients in the low-dose cohort, the mean annualized total FIX usage declined 75% after treatment with AMT-060. Only one patient remained on prophylactic therapy, but also displayed sustained disease characteristics and required less FIX concentrate after treatment with AMT-060. Safety results indicate that the therapy was overall well-tolerated.
“I am very encouraged by the stability of increased FIX activity of AMT-060 and the significant reduction in required infusions of factor replacement,” said Dr. Wolfgang Miesbach, professor of hematology at the University of Frankfurt, Germany. “This effect is particularly important because it is seen in severe patients with established joint disease who experienced a high frequency of joint bleeds despite intense use of prophylactic FIX prior to study entry.”
The five patients in the high-dose group are now in the early stages of follow-up. Data is expected to be presented before the end of the year.