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
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.
⁃ General
• Ability and willingness to provide informed consent
• Age ≥ 18 and ≤65 years at time of signing Informed Consent Form
• Ability and willingness to comply with the study protocol and to participate in all study visits and assessments in the investigator's judgement
• For candidates of childbearing potential: willingness to use a method of contraception
• Agreement not to take supplements other than vitamin A
⁃ Ocular Inclusion Criteria
• Both eyes must exhibit the RP phenotype with evidence of loss of night vision, gradual constriction of visual fields, and maintenance of visual acuity;
• In addition, an eye must meet the following criteria to be included in the study:
• Gradable EZ on a horizontal SD-OCT scan through the fovea center with width ≤ 8000 µm and ≥1500 µm and with well-defined truncation at both the nasal and temporal sides;
• BCVA ≥ ETDRS letter score of 61 (20/60 Snellen equivalent);
• Sufficiently clear ocular media and adequate pupillary dilation to allow good quality images sufficient for analysis and grading by central reading center.