New find offers hope for some Hemophiliacs

A team of researchers has improved the vectors for delivering human factor VIII (hFVIII) gene therapy to treat Hemophilia A.

The University of Pennsylvania study examined 42 combinations of promoters and enhancers for hFVIII gene expression to identify the optimal adeno-associated virus (AAV)-based gene therapy delivery vector constructs to take forward into development.

Evaluation of the different combinations in mice that lack factor VIII demonstrated the significant and differing effects the vector components had on liver-specific expression of the hFVIII transgene.

Researcher James M. Wilson and coauthors developed and compared the different AAV vectors to overcome the challenge of delivering the relatively large hFVIII gene and to achieve therapeutic levels of factor VIII gene expression.

They also compared the levels of antibody generated against the various AAV transgene delivery vectors.

"Dr. Wilson's group and their colleagues at Dimension Therapeutics continue to improve the design of AAV vectors designed to treat the more common form of hemophilia, hemophilia A," said Editor-in-Chief Terence R. Flotte. "These design improvements are crucial as the practical application of gene therapy for hemophilia progresses."

The study appears in the journal Human Gene Therapy.