Oral N-acetylcysteine for Retinitis Pigmentosa

Summary

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.

Conditions

• Retinitis Pigmentosa

Interventions

DRUG

N-acetylcysteine

After randomization, participants will be given about 10-months supply of study drug (intervention), with instructions to take 3 effervescent tablets in water twice a day. They will return to the clinic at M4.5 for evaluation and then at M9, M18, M27, M36, M40.5 and M45. At each in-clinic visit, drug reconciliation will occur. At each visit at Baseline, M9, M18, M27, M36, that is, every 9 months, participants will be given another 10-month supply of study drug.

DRUG

Placebo

After randomization, participants will be given about 10-months supply of placebo, with instructions to take 3 effervescent tablets in water twice a day. They will return to the clinic at M4.5 for evaluation and then at M9, M18, M27, M36, M40.5 and M45. At each in-clinic visit, efficacy and safety assessments will be done and drug reconciliation will occur. At baseline, M9, M18, M27, and M36 participants will be given another 10-month supply of placebo.

Sponsors & Collaborators

• National Eye Institute (NEI)

  collaborator NIH

• Duke University

  collaborator OTHER

• Emory University

  collaborator OTHER

• Massachusetts Eye and Ear Infirmary

  collaborator OTHER

• Mayo Clinic

  collaborator OTHER

• Medical College of Wisconsin

  collaborator OTHER

• Retina Foundation of the Southwest

  collaborator OTHER

• Stanford University

  collaborator OTHER

• University of California, Davis

  collaborator OTHER

• University of Florida

  collaborator OTHER

• University of Iowa

  collaborator OTHER

• University of Miami

  collaborator OTHER

• University of Michigan

  collaborator OTHER

• University of Minnesota

  collaborator OTHER

• University of Oklahoma

  collaborator OTHER

• University of Southern California

  collaborator OTHER

• University of Utah

  collaborator OTHER

• University of Washington

  collaborator OTHER

• University of Wisconsin, Madison

  collaborator OTHER

• Vanderbilt University

  collaborator OTHER

• Vitreo Retinal Associates, PA

  collaborator UNKNOWN

• University of Houston

  collaborator OTHER

• Medical University of Graz

  collaborator OTHER

• McGill University

  collaborator OTHER

• Universität Tübingen

  collaborator OTHER

• Radboud University Medical Center

  collaborator OTHER

• University of Amsterdam

  collaborator OTHER

• University Hospital, Basel, Switzerland

  collaborator OTHER

• University College London Hospitals

  collaborator OTHER

• Northwestern University

  collaborator OTHER

• University of Pennsylvania

  collaborator OTHER

• Johns Hopkins University

  lead OTHER

Principal Investigators

• Peter A Campochiaro, MD · Johns Hopkins University

• Xiangrong Kong · Johns Hopkins University

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

65 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2023-10-11

Primary Completion

2029-05-31

Completion

2030-05-31

FDA Drug

Yes

Countries

• United States
• Austria
• Canada
• Germany
• Netherlands
• Switzerland
• United Kingdom

Study Locations