Oral N-acetylcysteine for Retinitis Pigmentosa

Retinitis pigmentosa (RP) is an inherited retinal degeneration caused by one of several mistakes in the genetic code. Such mistakes are called mutations. The mutations cause degeneration of rod photoreceptors which are responsible for vision in dim illumination resulting in night blindness. After rod photoreceptors are eliminated, gradual degeneration of cone photoreceptors occurs resulting in gradual constriction of side vision that eventually causes tunnel vision. Oxidative stress contributes to cone degeneration. N-acetylcysteine (NAC) reduces oxidative stress and in animal models of RP it slowed cone degeneration. In a phase I clinical trial in patients with RP, NAC taken by month for 6 months caused some small improvements in two different vision tests suggesting that long-term administration of NAC might slow cone degeneration in RP. NAC Attack is a clinical trial being conducted at many institutions in the US, Canada, and Europe designed to determine if taking NAC for several years provides benefit in patients with RP.

NCT Number	NCT05537220
Lead Sponsor	Johns Hopkins University Collaborators: National Eye Institute (NEI), Duke University, Emory University, Massachusetts Eye and Ear Infirmary, Mayo Clinic, Medical College of Wisconsin, Retina Foundation of the Southwest, Stanford University, University of California, Davis, University of Florida, University of Iowa, University of Miami, University of Michigan, University of Minnesota, University of Oklahoma, University of Southern California, University of Utah, University of Washington, University of Wisconsin, Madison, Vanderbilt University, Vitreo Retinal Associates, PA, University of Houston, Medical University of Graz, McGill University, Universität Tübingen, Radboud University Medical Center, University of Amsterdam, University Hospital, Basel, Switzerland, University College London Hospitals, Northwestern University, University of Pennsylvania
Conditions	Retinitis Pigmentosa
Enrollment	485 participants
Start Date	2023-10-11
Primary Completion	2029-05 (estimated)
Study Completion	2030-05 (estimated)
Updated on ClinicalTrials.gov	2026-06-15