Gene therapy may reduce treatment burden associated with AMD
PHILADELPHIA — Existing techniques enable the application of gene therapy for age-related macular degeneration, a clinician said here.
“I think we’re in the most exciting period advancing forward with respect to biologics and the treatments of retinal diseases,” Elias Reichel, MD, said at Macula 2014. “The idea is that this is going to last for a prolonged period of time. Hopefully, we’ll avoid some of the issues with the burden of treatment with multiple injections of either small molecules or biologics.”
The retina is easily accessible with existing techniques such as intravitreal injection, subretinal injection, pars plana vitrectomy, internal limiting membrane removal and laser treatment, individually or in various combinations, Reichel said.
“The key, though, is adequately infecting the retina to achieve therapeutic protein expression levels,” he said. “I believe that at least one of these approaches will work, if not several.”
Adeno-associated virus (AAV) is widely used for ocular gene therapy. Ongoing study is focused on AAV2.
Currently, phase 1 studies are being undertaken by Genzyme/Sanofi, Oxford Biomedica/Sanofi and Avalanche. Hemera Biosciences and two groups at Cornell University are undertaking preclinical studies.
Reichel and colleagues at Hemera Biosciences are studying the use of the CD59 gene in preventing the development of wet AMD by blocking the last step of the complement cascade.
A retinal prosthesis being developed by Sheila Nirenberg, PhD, at Cornell involves a camera, a light source and a transducer. The light interacts with AAV2 injected into the vitreous, expressing channel rhodopsin-2 and activating the ganglion cells, Reichel said.
Disclosure: Reichel is a co-founder of Hemera Biosciences.