Dr. Steven Pipe, Pediatric Medical Director of the Hemophilia and Coagulation Disorders Program in Ann Arbor Michigan, presented an update at the World Federation of Hemophilia virtual summit on UniQure’s AMT-061 gene therapy trial in hemophilia B. This therapy makes use of the AAV5 vector and the high-expression Padua-type factor IX gene.
Three patients received the dose of 2 X 1013 vg/kg. Interestingly, the presence of pre-existing antibodies to the AAV5 vector was not an exclusionary criterion. Previous research in the AMT-060 Phase 1/2 trial had revealed that these antibodies did not result in an immune response and loss of FIX expression. Even without immunosuppression using steroids, there was no evidence of transaminitis (raised liver enzymes).
After 52 weeks, the FIX levels of the three people ranged from 31% to 50% with a mean of 41%. None of the people experienced bleeding.
UniQure’s research is continuing in the Phase 3 HOPE-B trial with 56 subjects at the same dose. Recruitment is complete. (N.B. On June 24, CSL Behring acquired world-wide rights to UniQure’s hemophilia B gene therapy technology.)
