Age-Related Macular Degeneration: A ‘20/20 Vision’ for Better Care

Old man in glasses having difficulties to read a book

(DGIwire) – What do actors Dabney Coleman, Roseanne Barr and Dame Judi Dench have in common? All three suffer from age-related macular degeneration (AMD), a condition that is the leading cause of vision loss, affecting more than 10 million Americans—more than cataracts and glaucoma combined, according to the American Macular Degeneration Foundation.

AMD is a common eye condition and a leading cause of vision loss among people age 50 and older, reports the National Eye Institute, a division of the National Institutes of Health. It causes damage to the macula, a small spot near the center of the retina and the part of the eye needed for sharp, central vision, which lets people see objects that are straight ahead. In some people, AMD advances so slowly that vision loss does not occur for a long time. In others, the disease progresses faster and may lead to a loss of vision in one or both eyes. As AMD progresses, a blurred area near the center of vision is a common symptom.

“In patients with ‘wet’ AMD, blood vessels in the eye can leak blood and fluid, causing loss of vision,” says Dr. Geert Cauwenbergh, President and CEO of RXi Pharmaceuticals. “Even with standard treatment that reduces new blood vessel growth, the disease can progress and trigger irreversible retinal scarring—also known as subretinal fibrosis—which leads to even further vision loss. Currently, there are no approved therapeutics in the U.S. for the treatment and prevention of subretinal fibrosis.”

But what if we could block the proteins that form the scarring from doing their destructive work in the first place? RXi Pharmaceuticals—harnessing work by Nobel Prize-winning biologist Craig C. Mello, Ph.D., who chairs the company’s Scientific Advisory Board—is showing it to be possible.

Here’s how it works. We all learned “DNA makes RNA makes proteins” in school. Mello has shown in studies how a naturally occurring phenomenon called RNA interference—“RNAi” for short—can destroy particular RNA molecules before they can form proteins. The theory is, “Reduced scar proteins, reduced retinal scarring.” The company has developed a therapeutic platform of self-delivering RNAi compounds, called sd-rxRNA®. The first of these compounds, RXI-109, is designed to reduce the expression of connective tissue growth factor (CTGF), a critical agent of scar formation in the eye and skin.

The company is conducting an ongoing Phase 1/2 clinical trial in patients with advanced “wet” AMD to evaluate the safety and clinical activity of RXI-109 to prevent the progression of retinal scarring. If successful, the treatment could potentially preserve vision for a longer time and benefit patients with other eye diseases involving scarring, such as proliferative vitreoretinopathy and proliferative diabetic retinopathy.

“Enhancing the current standard of care for those with ‘wet’ AMD would greatly benefit the millions of people who experience this condition,” adds Dr. Cauwenbergh. “We owe it to everyone whose vision is failing as a result of AMD to help mitigate their symptoms.”