A multi-year, ongoing study suggests that a new kind of gene therapy for hemophilia B could be safe and effective for human patients. Published in the journal Science Translational Medicine, the research showed that a reprogrammed retrovirus could successfully transfer new factor IX (clotting) genes into animals with hemophilia B to dramatically decrease spontaneous bleeding. Thus far, the new therapy has proven safe. "The result was stunning," said Timothy Nichols, MD, director of the Francis Owen Blood Research Laboratory at the University of North Carolina School of Medicine and co-senior author of the paper. "Just a small amount of new factor IX necessary for proper clotting produced a major reduction in bleeding events. It was extraordinarily powerful." The idea behind gene therapy is that doctors could give hemophilia patients a one-time dose of new clotting genes instead of a lifetime of multiple injections of recombinant factor IX that until very recently had to be given several times a week. A new FDA-approved hemophilia treatment lasts longer than a few days but patients still require injections at least once or twice a month indefinitely. This new gene therapy approach, like other gene therapy approaches, would involve a single injection and could … Continue reading →

Using mutant protein, CHOP hematologist safely removes unwanted antibodies, reverses hemophilia in dog model of bleeding disease Using gene therapy to produce a mutant human protein with unusually high blood-clotting power, scientists have successfully treated dogs with the bleeding disorder hemophilia, without triggering an unwanted immune response. In addition, the "turbocharged" clotting factor protein eliminated pre-existing antibodies that often weaken conventional treatments for people with hemophilia. "Our findings may provide a new approach to gene therapy for hemophilia and perhaps other genetic diseases that have similar complications from inhibiting antibodies," said the study leader, Valder R. Arruda, M.D., Ph.D., a hematology researcher at The Children's Hospital of Philadelphia (CHOP). Arruda and colleagues published their animal study results in the print edition of Blood on March 5. Hemophilia is an inherited bleeding disorder that famously affected European royal families descended from Queen Victoria. Most commonly occurring in two types, hemophilia A and hemophilia B, the disease impairs the blood's ability to clot, sometimes fatally. When not fatal, severe hemophilia causes painful, often disabling internal bleeding and joint damage. Doctors treat hemophilia with frequent intravenous infusions of blood clotting proteins called clotting factors, but these treatments are expensive and time-consuming. Moreover, some … Continue reading →