N-acetylcysteine (NAC) to help preserve vision in retinitis pigmentosa
Official title: NAC Attack, A Phase-3, Multicenter, Randomized, Placebo-Controlled Trial in Patents with Retinitis Pigmentosa
Funded at Johns Hopkins University · NIH-11307042 · Data updated 2026-11-12
This trial tests whether taking oral NAC daily can slow cone loss and help people with retinitis pigmentosa keep more vision.
Quick facts
| Grant type | NIH-funded research |
|---|---|
| Study type | NIH-funded research |
| Funding institution | Johns Hopkins University NIH-funded |
| Lab location | 1 site (Baltimore, United States) |
| Project start | March 17, 2022 |
| Project end | February 28, 2027 |
| Funding year | 2026 |
| Award (this year) | $344,858 |
| NIH project number | 5UG1EY033286-05 |
| Project ID | NIH-11307042 on NIH RePORTER |
Who could benefit from this research
✓Could help
People diagnosed with retinitis pigmentosa who still have measurable cone structure or function, can take oral medication, and can attend regular study visits are the likely candidates.
✕Less likely to help
People with very advanced disease and little remaining cone tissue, or those with medical reasons they cannot take NAC, are less likely to benefit from this trial.
What this research studies
This is a phase 3, multicenter, randomized, double-masked trial comparing long-term oral NAC to a placebo in people with retinitis pigmentosa. Participants are randomly assigned to receive NAC or placebo, take study medication (previous work used up to 1800 mg twice daily), and come to regular clinic visits for eye imaging and vision tests. The main outcome is cone survival measured by ellipsoid zone width on OCT scans, with other functional vision measures tracked over time. About 438 participants will be enrolled across multiple centers to see if the benefits seen in animals and a small earlier human trial hold up in a larger group.
Why it matters
Potential benefit: If successful, long-term NAC could slow cone degeneration and help preserve visual field and acuity for people with retinitis pigmentosa.
How similar studies have gone: Animal models showed strong cone protection with antioxidants and a small 30-patient human trial found NAC was safe and produced modest short-term cone-function improvements, so this larger trial follows promising early data.
Where this research is happening
-
Johns Hopkins University
Baltimore, United States Active
Researchers
- Principal investigator: Campochiaro, Peter a — Johns Hopkins University
- Study coordinator: Campochiaro, Peter a
Related research
Other NIH-funded projects on the same topics.
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Inflammation in MERTK-related retinitis pigmentosa
This project aims to understand whether losing the MERTK gene causes retinal inflammation that leads to vision loss in people with MERTK-related retinitis pigmentosa.
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Enhancing cone survival in RP through targeted cell-specific CRISPR therapy
A patient-friendly look at a new approach to protect cone cells in retinitis pigmentosa using precise gene editing to support vision.
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Oral, once-daily MC16 medicine for retinitis pigmentosa
A gene-mutation-agnostic pill (MC16) is being studied to help people with retinitis pigmentosa by addressing a common cellular problem in the eye.
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Role of IPM Proteoglycans in Retinal Health and Inherited Blindness
This grant studies how specific retinal extracellular matrix proteins (IMPG1 and IMPG2) affect eye health and contribute to retinitis pigmentosa, with potential implications for people who have or are at risk for inherited blindness.
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NAC Attack: a late-stage trial for preserving vision in RP patients
A large, multi-site study is testing whether taking a daily NAC pill can help people with retinitis pigmentosa keep more of their vision.
-
Non-invasive biomarker for mitochondria health in retinitis pigmentosa
Aims to test a new, non-invasive OCT-based biomarker to explain and predict how mitochondria function affects cone cells in people with retinitis pigmentosa.
About this research
- This is an active NIH-funded research project — typically early-stage science, not a clinical trial accepting patient enrollment.
- Some NIH-funded labs run parallel clinical studies or seek volunteers for related work. To check, contact the principal investigator or institution listed above.
- For full project details, budget, and progress reports, visit the official NIH RePORTER page.