May 6, 2022

Promising Results from Lab Study of Gene Therapy for Cone-Rod Dystrophy

Eye On the Cure Research News

The study is an important step toward a clinical trial of the approach

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Researchers from the University of Oxford rescued photoreceptor function and retinal structure in a mouse model of cone-rod dystrophy caused by mutations in the gene CDHR1. Results from the preclinical study were reported by Imram Yusuf, MD, PhD, a clinical researcher from the University of Oxford Medical Sciences Division, at the 2022 meeting of the Association for Research in Vision and Ophthalmology (ARVO) held in Denver, May 1–5.

Cone-rod dystrophy is an inherited retinal condition causing both loss of central and peripheral vision. More than two-dozen genes, each of which, when mutated, can cause cone-rod dystrophy. Approximately 200,000 people around the world have cone-rod dystrophy.

In the study, mice with CDHR1 mutations were treated with a gene therapy that used an adeno-associated virus serotype 8 (AAV8), a safe, human-engineered virus, to deliver healthy copies of CDHR1 to cells in the retina. The gene therapy was delivered by a one-time, subretinal injection.

Mice receiving the gene therapy had improved retinal sensitivity as measured by an electroretinogram (ERG) and improved visual acuity as measured by an optomotor test. Also, the gene therapy preserved retinal structure as captured by optical coherence tomography (OCT). The researchers believe that photoreceptor outer segments, the light-sensing portion of the cells, regenerated, as well.

Dr. Yusuf said that a follow-on clinical trial in patients with CDHR1-associated retinal degeneration is warranted.