The Wilmer Eye Institute, Johns Hopkins Medicine has received two awards totaling more than $20 million from the National Eye Institute at the National Institutes of Health, both of which will be used for a six-year clinical trial investigating a potential treatment for the most common inherited retinal disease, retinitis pigmentosa.

The disease causes retinal cells in the eye, or cells that sense light, to break down, resulting in gradual and permanent vision loss. Currently, retinitis pigmentosa has no treatments.

Researchers hope to change the landscape of retinitis pigmentosa care with these awards, which they will use to look at whether the drug N-acetyl cysteine (NAC) may slow or halt vision loss from the condition when compared to a placebo. Previously approved by the Food and Drug Administration to treat acetaminophen overdose, NAC is an antioxidant drug that reduces oxidative stress, which is a molecular mechanism in the body thought to play a role in retinitis pigmentosa. Previous animal studies, including those conducted by the Campochiaro laboratory at the Wilmer Eye Institute, showed that high doses of NAC reduced cell damage caused by oxidative stress, while simultaneously reducing vision loss.

The Wilmer-led trial testing NAC in a large group of human participants is just beginning in the United States, Canada and Europe, and will involve approximately 450 people with retinitis pigmentosa from more than 30 medical centers.

During the double-blind clinical trial, participants will be randomly assigned either a daily oral dose of NAC or a placebo pill. Both the researchers and participants will be unaware of their assignments. Then, over the course of the study, participants will receive retinal imaging and vision testing at regular intervals to monitor the health of the retina and their vision status. Blood tests will also be conducted to monitor overall health and help ensure participants’ safety.

The awards will be largely used to fund the logistical and collaborative clinical aspects of the trial. One award will help fund the study chair’s office, led by Peter Campochiaro, M.D., the Eccles Professor of ophthalmology and neuroscience at the Johns Hopkins University School of Medicine, while the other award funds the trial’s coordinating center. The center will help with the distribution of the study drug, clinical testing for participants during the trial and monitoring of study conduct, explains Xiangrong Kong, Ph.D., associate professor of ophthalmology at the Johns Hopkins University School of Medicine and of biostatistics and epidemiology at the Johns Hopkins Bloomberg School of Public Health. Kong is the director of the trial’s coordinating center and the senior biostatistician of the study.

“The scale of this study, trying to find a first-of-its-kind and safe treatment for a devastating eye condition alongside its geographic coverage, helps make this study highly significant,” says Kong.

Additional information about the trial can be found here, on the study’s webpage.