Factor IX gene therapy for hemophilia.

Using gene therapy to produce systemic levels of human factor IX for the treatment of hemophilia B has been clinically evaluated using viral-based vectors. The efficacy of this approach has been limited because of immune responses against the viral components. An alternative approach is to use physical methods such as in vivo electroporation to deliver plasmid DNA, thereby avoiding some of the complications associated with viral-based delivery systems. A method describing intramuscular injection of plasmid formulated with an anionic polymer and followed by electroporation, which can produce high transfection efficiency and high levels of systemic factor IX protein following a single administration, is provided here.