FDA grants orphan designation for AMT's hemophilia gene therapy program

Amsterdam Molecular Therapeutics (Euronext: AMT), a leader in the field of human gene therapy, announced today that the U.S. Food and Drug Administration (FDA) has granted orphan drug designation to its gene therapy program for the treatment of hemophilia B. Orphan designation in the U.S. could provide up to seven years market exclusivity on regulatory approval. Orphan designation for AMT's hemophilia program in the European Union was granted in November 2011.

AMT's hemophilia B program, which consists of an adeno-associated viral (AAV) vector containing the human factor IX gene, is being investigated in a Phase I/II study conducted by St. Jude's Children's Research Hospital (Memphis, USA) and University College London (UK). Promising data from an initial 6 patients, recently published in the New England Journal of Medicine (N Engl J Med 2011; 365:2357-2365), shows that gene therapy administration resulted in a reduced need for protein replacement treatment, the standard care for hemophilia patients.  AMT is preparing for additional clinical development work to establish safety, tolerability and proof-of-concept with a factor IX gene therapy produced using its proprietary AAV production system.

"U.S. orphan designation provides additional support for our hemophilia B gene therapy program and supplements the designation in the EU received in November," said Jörn Aldag, CEO of AMT. "The early clinical success seen with the program to date by our partners is very encouraging. We will build on this success in the coming months."