Studies Support Gene Therapy for Retinal Conditions
Results point to safety, possible efficacy of gene-bearing vector for Leber's congenital amaurosis
MONDAY, April 28 (HealthDay News) -- A pair of studies published online April 27 in the New England Journal of Medicine offer support for research into gene therapy to treat Leber's congenital amaurosis (LCA), a group of inherited disorders marked by retinal degeneration and severe vision loss.
Albert M. Maguire, M.D., of the University of Pennsylvania in Philadelphia, and colleagues describe using a recombinant adeno-associated virus to carry complementary DNA of RPE65, a gene expressed in retinal pigment epithelium. Mutations are associated with degeneration of rods and cones. The researchers injected the vector into the subretinal space of the eye with worse function in three young adult patients with the LCA2 form of the disease, associated with the RPE65 mutation. All showed modest signs of retinal function improvement, with no evidence of adverse effects from the injection.
In the other study, James Bainbridge, Ph.D., of University College London in the U.K., and colleagues report on treating three young adults who had severe retinal dystrophy due to missense mutations in RPE65. Each received an injection of recombinant adeno-associated virus vector 2/2 expressing RPE65 complementary DNA under the retina in the eye with the poorest acuity. Though no patients showed significant change in visual acuity, one had significant improvement in visual function on microperimetry and dark-adapted perimetry. The procedures carried no serious adverse effects.
"The preliminary results from these investigations suggest that in the short term, the procedure is safe. Moreover, the data are suggestive of efficacy," writes Joan W. Miller, M.D., of Harvard Medical School in Boston, in an accompanying editorial.
Maguire and some co-authors shared a variety of disclosures, including patents and relationships with pharmaceutical companies. Bainbridge and some co-authors also report disclosures regarding inventions and financial relationships with biotech companies. Miller reports a financial relationship with Genzyme.