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Alum Gives Seminar on Gene Therapy Treatment for Blindness
Published: November 7, 2012
In mid-October, ENC Alum and Trustee, Daniel Chung (Biology, ’85), presented in Shrader Lecture Hall on The Gene Therapy Clinical Trials for Childhood Blindness entitled, “And the Blind Will See.”
Leber congenital amaurosis (LCA) is an autosomal recessive disease causing blindness by affecting the retina. The disease has an early onset at 5 to 7 years of age, and there are 3 thousand cases of LCA in the United States alone, with not current treatment or cure. The gene therapy clinical trial, conducted by the Children’s Hospital of Pennsylvania and University of Pennsylvania, is having success treating patients, allowing them to regain vision. Should this clinical trial prove successful and pass the regulations put forth by the FDA, this gene therapy could be the first to be approved in the US. Treatment is an injection of an adeno-associated virus, altered to contain copies of the normal or “good” gene, into the eye.
The first stage of testing, known as the pre-clinical stages, involved treating dogs with LCA. An injection was given to one of two dogs. Results were visibly favorable to the dog given the treatment, while the other still could not see. With success in the pre-clinical stages, the team looked toward proceeding to the clinical trials.
To conduct the clinical trial, the study needed to gain approval from a number of organizations including the FDA. After 7 years, the gene therapy was approved to enter the clinical stages, and in 2008 the first patient was treated. Tests are conducted pre- and post-treatment to determine the success of the gene therapy including reading line charts and ERGs.
Chung was responsible for creating another test; an obstacle course to test the practical enhancements the gene therapy gives the patients. Because only one eye is injected for treated, the baseline test is done with the treated eye covered, and the second test is done with the untreated eye covered. You can watch video of the obstacle course here.
Chung concluded his presentation suggesting that not only does this treatment have the potential to be the first approved gene therapy treatment in the United States, it provides hope for those diagnosed with Leber Congenital Amaurosis and other visual genetic disorders.