Philadelphia gene therapy trial restores vision

    A decade ago, treatment complications killed a teenager undergoing gene therapy at the University of Pennsylvania. That loss sent a chill throughout the field. Many questioned the prudence and safety of the attempts to replace faulty genes with “good” ones. This week gene therapy researchers at The Children’s Hospital of Philadelphia and the University of Pennsylvania are reporting a success.

    A decade ago, treatment complications killed a teenager undergoing gene therapy at the University of Pennsylvania. That loss sent a chill throughout the field. Many questioned the prudence and safety of the attempts to replace faulty genes with “good” ones. This week gene therapy researchers at The Children’s Hospital of Philadelphia and the University of Pennsylvania are reporting a success.

    Listen:

    [audio:091026tegene.mp3]

    Nine-year-old Corey Haas used to be legally blind. He saw shapes and shadows but used a cane to steer clear of all the things he couldn’t see. When he went out to play, his parents tagged along, just to be safe.

    How the therapy works
    How the therapy works
    Haas: Well, before I used to ride my bike just in front of the house, now I just ride around the neighborhood, with no one with me.

    Corey, who’s from Upstate New York, was born with LCA, Leber’s Congenital Amaourosis. It’s an inherited eye disease that was stealing his sight.

    Treatment DNA was cloned in Dr. Jean Bennett’s laboratory at Penn Medicine. Doctors injected those genes into slowly dying cells in Corey’s eye.

    Bennett:
    If you deliver the normal copy of the gene, then that can serve as a factory to produce the protein which is missing in those cells, so it basically corrects the bio-chemical defect in those cells.

    That jump started a process to turn on light receptors in the eye. Now Corey’s reading large-print books and sees well enough to play soccer.

    The trial was a very small study of 12 people with the same rare progressive illness. The kids in the study had the greatest improvements. Bennett can’t say it’s a cure, but the treatment has altered the course of Corey’s disease.

    The study findings are reported in the latest online edition of The Lancet.

    More info:
    Read the complete press release from Children’s Hospital of Philadelphia

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