Send to

Choose Destination
See comment in PubMed Commons below
Mol Ther. 2011 Mar;19(3):442-9. doi: 10.1038/mt.2010.240. Epub 2010 Nov 16.

Efficacy and safety of long-term prophylaxis in severe hemophilia A dogs following liver gene therapy using AAV vectors.

Author information

Department of Genetics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.


Developing adeno-associated viral (AAV)-mediated gene therapy for hemophilia A (HA) has been challenging due to the large size of the factor VIII (FVIII) complementary DNA and the concern for the development of inhibitory antibodies to FVIII in HA patients. Here, we perform a systematic study in HA dogs by delivering a canine FVIII (cFVIII) transgene either as a single chain or two chains in an AAV vector. An optimized cFVIII single chain delivered using AAV serotype 8 (AAV8) by peripheral vein injection resulted in a dose-response with sustained expression of FVIII up to 7% (n = 4). Five HA dogs administered two-chain delivery using either AAV8 or AAV9 via the portal vein expressed long-term, vector dose-dependent levels of FVIII activity (up to 10%). In the two-chain approach, circulating cFVIII antigen levels were more than fivefold higher than activity. Notably, no long-term immune response to FVIII was observed in any of the dogs (1/9 dogs had a transient inhibitor). Long-term follow-up of the dogs showed a remarkable reduction (>90%) of bleeding episodes in a combined total of 24 years of observation. These data demonstrate that both approaches are safe and achieve dose-dependent therapeutic levels of FVIII expression, which supports translational studies of AAV-mediated delivery for HA.

[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science Icon for PubMed Central
    Loading ...
    Support Center