Nanoparticle-Based Gene Therapy Preserves Vision in Lab Study for Stargardt Disease

August 17, 2012

Dr. Muna Naash, a Foundation-funded researcher from the University of Oklahoma Health Sciences Center, used a nanoparticle-based gene therapy to provide long-term preservation of vision in mice with Stargardt disease. A study recently published online in the Journal of Clinical Investigation shows that the innovative treatment approach has the potential to be an advantageous alternative for delivering therapeutic genes to the retina for a variety of conditions.
Current gene therapies in early clinical trials for retinal disease — including Oxford BioMedica’s StarGen™ treatment for Stargardt disease — employ gene delivery technologies based on human-engineered viruses, including adeno-associated viruses and lentiviruses. While those viral systems are performing well thus far, they do have limitations. Foremost, they do not have the capacity for delivering very large corrective genes, including those that would be used to treat Usher syndrome type 2A (USH2A), Leber congenital amaurosis caused by defects in the gene CEP290 and certain forms of retinitis pigmentosa (RP).

In addition to the Stargardt disease treatment, the Foundation is funding Dr. Naash to develop nanoparticle-based gene therapies for USH2A and forms of autosomal dominant RP and cone-rod dystrophy caused by defects in the gene PRPH2 (also known as RDS).

Some experts believe that nanoparticles — tiny manmade particles that are 1/10,000,000th of an inch or smaller — may be a highly safe medium for delivering genes to the retina, because the body is unlikely to have an immune reaction to them. However, the safety profile for viral gene delivery has been excellent in early clinical trials for retinal diseases.

“The bottom line is that it is best that we pursue multiple options for gene delivery, especially at this early stage of development,” says Dr. Stephen Rose, chief research officer, Foundation Fighting Blindness. “We don’t want to put all of our eggs in one basket. It may turn out that viral delivery is better for some conditions and nanoparticles are better for others.”