Novel approaches to hemophilia therapy: successes and challenges.

New therapies for hemophilia A and hemophilia B will likely continue to change clinical practice. Ranging from extended half-life to nonfactor products and gene therapy, these innovative approaches have the potential to enhance the standard of care by decreasing infusion frequency to increase compliance, promoting prophylaxis, offering alternatives to inhibitor patients, and easing route of administration. Each category has intrinsic challenges that may limit the broader application of these promising therapies. To date, none specifically address the challenge of dispersing treatment to the developing world.