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Active, not recruiting Phase 3 Interventional

Oral N-acetylcysteine for Retinitis Pigmentosa

ClinicalTrials.gov ID: NCT05537220

Public ClinicalTrials.gov record NCT05537220. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.

ClinicalTrials.gov public records Last synced Sep 6, 2026, 9:29 PM EDT

Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.

Official title

NAC Attack, A Phase III, Multicenter, Randomized, Parallel, Double Masked, Placebo-Controlled Study Evaluating the Efficacy and Safety of Oral N-Acetylcysteine in Patients With Retinitis Pigmentosa

Brief summary

Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.

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.

Study identification

NCT ID
NCT05537220
Recruitment status
Active, not recruiting
Study type
Interventional
Phase
Phase 3
Lead sponsor
Johns Hopkins University
Other
Enrollment
485 participants

Conditions and interventions

Interventions

Drug

Eligibility (public fields only)

Age range
18 Years to 65 Years
Sex
All
Healthy volunteers
Healthy volunteers not accepted

This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.

Study timeline

Start date
Oct 10, 2023
Primary completion
Apr 30, 2029
Completion
Apr 30, 2030
Last update posted
Jun 14, 2026

2023 – 2030

United States locations

U.S. sites
24
U.S. states
16
U.S. cities
24
Facility City State ZIP Site status
University of California - Davis, Department of Ophthalmology & Vision Science Davis California 95817
University of Southern California, Keck School of Medicine Los Angeles California 90089
University of California - San Francisco, Department of Ophthalmology San Francisco California 94158
Stanford University, Byers Eye Institute Stanford California 94303
Vitreo Retinal Associates Gainesville Florida 32607
University of Florida - Jacksonville, UF Health Jacksonville Jacksonville Florida 32209
University of Miami, Bascom Palmer Eye Institute Miami Florida 33136
Emory University, Emory Eye Center Atlanta Georgia 30322
University Of Illinois At Chicago Chicago Illinois 60612
Northwestern University Evanston Illinois 60208
University of Iowa, Carver College of Medicine Iowa City Iowa 52242
Wilmer Eye Institute- Johns Hopkins University Baltimore Maryland 21287
Harvard University, Mass. Eye and Ear Boston Massachusetts 02114
University of Michigan, Kellogg Eye Center Ann Arbor Michigan 48105
University of Minnesota, Department of Ophthalmology and Visual Neurosciences Minneapolis Minnesota 55455
Mayo Clinic, Department of Ophthalmology Rochester Minnesota 55905
University of Oklahoma, Dean McGee Eye Institute Oklahoma City Oklahoma 73104
Scheie Eye Institute Philadelphia Pennsylvania 19104
Vanderbilt University, Vanderbilt Eye Institute Nashville Tennessee 37211
Retina Foundation of the Southwest Dallas Texas 75231
University of Utah, Moran Eye Center Salt Lake City Utah 84132
University of Washington, Department of Ophthalmology Seattle Washington 98109
University of Wisconsin - Madison, McPherson Eye Research Institute Madison Wisconsin 53705
Medical College of Wisconsin, The Eye Institute Milwaukee Wisconsin 53226

Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.

Non-U.S. locations

This page focuses on the U.S. directory. The official record also lists 7 non-U.S. sites.

About this trial record page

What this page shows
Public field values for ClinicalTrials.gov record NCT05537220, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
What this page does not do
No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
Where the data comes from
Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
Last refresh
Last update posted Jun 14, 2026 · Synced Sep 6, 2026

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Open the official record

The complete protocol, eligibility criteria, and contact information for NCT05537220 live on ClinicalTrials.gov.

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