What is the mechanism of action of this treatment?

Retinitis Pigmentosa (RP) is characterized by the degeneration of rod and cone photoreceptors in the retina, leading to symptoms such as night blindness and peripheral vision loss. One of the treatments being studied for RP is N-acetylcysteine (NAC), which works by reducing oxidative stress—a contributing factor to cone degeneration. By mitigating oxidative damage, NAC aims to slow the progression of photoreceptor loss, potentially preserving vision for a longer period. This is particularly important for RP patients as it addresses one of the underlying mechanisms of the disease, offering hope for improved management and quality of life.

What side effects are associated with this type of intervention?

Common treatments for Retinitis Pigmentosa (RP) that focus on reducing oxidative stress include N-acetylcysteine (NAC) and omega-3 fatty acids. NAC has been shown to cause some mild improvements in vision tests, but potential side effects include gastrointestinal discomfort and, in rare cases, allergic reactions. Omega-3 fatty acids, while generally well-tolerated, can cause side effects such as gastrointestinal upset, fishy aftertaste, and increased bleeding risk in high doses. Overall, these treatments aim to slow the progression of RP by mitigating oxidative damage to retinal cells.

What prior FDA approvals exist?

As of now, there are no FDA-approved treatments specifically for Retinitis Pigmentosa that focus on reducing oxidative stress similar to N-acetylcysteine (NAC). However, NAC is being studied in clinical trials for its potential to slow cone degeneration by reducing oxidative stress. Other treatments for RP are generally supportive or focus on managing symptoms rather than addressing the underlying oxidative stress.

What other types of research exist?

Promising novel alternatives to N-acetylcysteine for Retinitis Pigmentosa patients in 2024 may include gene therapy approaches, such as those targeting specific genetic mutations causing RP, and neuroprotective agents that aim to preserve retinal cells. Additionally, other antioxidants or compounds that reduce oxidative stress, like vitamin A derivatives or novel small molecules, could be considered based on ongoing research and clinical trials.

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Antioxidant

N-acetylcysteine for Retinitis Pigmentosa (NAC Attack Trial)

Phase 3

Recruiting

Research Sponsored by Johns Hopkins University

Eligibility Criteria Checklist

Specific guidelines that determine who can or cannot participate in a clinical trial

Must have

Be older than 18 years old

Timeline

Screening 3 weeks

Treatment Varies

Follow Up baseline, 4.5 months, 9 months, 18 months, 27 months, 36 months, 40.5 months, 45 months

Awards & highlights

Pivotal Trial

Summary

This trial is testing if N-acetylcysteine (NAC) can help slow down vision loss in people with Retinitis Pigmentosa (RP). RP is a genetic condition that causes gradual vision loss. NAC reduces damage caused by too much oxygen around eye cells, potentially protecting vision. N-acetylcysteine (NAC) has been shown to reduce oxidative damage and increase cone function/survival in studies related to RP.

Who is the study for?

Adults aged 18-65 with Retinitis Pigmentosa (RP), willing to consent and follow the study protocol, not taking supplements other than vitamin A, and using contraception if of childbearing potential. Excluded are those with uncontrolled blood pressure, recent participation in another drug/device trial, certain genetic disorders like phenylketonuria or fructose intolerance, active cancer within a year (with exceptions), eye conditions that could affect results, severe myopia over -8 diopters, liver disease, cystic fibrosis, asthma/COPD or renal failure.

What is being tested?

The clinical trial is testing whether long-term use of N-acetylcysteine (NAC) can slow down cone degeneration in patients with RP by reducing oxidative stress. Participants will either receive NAC or a placebo for several years across multiple locations internationally.

What are the potential side effects?

While specific side effects for this trial aren't listed here, common side effects of N-acetylcysteine may include nausea, vomiting, rash and fever. Allergic reactions are possible but rare.

Timeline

Screening ~ 3 weeks3 visits

Treatment ~ Varies

Follow Up ~ baseline, 4.5 months, 9 months, 18 months, 27 months, 36 months, 40.5 months, 45 months

Screening ~ 3 weeks

Treatment ~ Varies

Follow Up ~baseline, 4.5 months, 9 months, 18 months, 27 months, 36 months, 40.5 months, 45 months

This trial's timeline: 3 weeks for screening, Varies for treatment, and baseline, 4.5 months, 9 months, 18 months, 27 months, 36 months, 40.5 months, 45 months for reporting.

Treatment Details

Study Objectives

Study objectives can provide a clearer picture of what you can expect from a treatment.

Primary study objectives

Progressive change of ellipsoid zone (EZ) width

Secondary study objectives

Change in best-corrected visual acuity

Change in mean macular sensitivity measured by microperimetry (MP)

Other study objectives

Change in BCVA

Change in cone reflectivity measured by AOSLO

Change in cone regularity measured by AOSLO

+7 more

Awards & Highlights

Pivotal Trial

The final step before approval, pivotal trials feature drugs that have already shown basic safety & efficacy.

Trial Design

2Treatment groups

Experimental Treatment

Placebo Group

Group I: Group 1 - N-acetylcysteineExperimental Treatment1 Intervention

This is the intervention group. Patients in this group will be receiving 1800 mg of N-acetylcysteine in the form of 3 effervescent 600 mg tablets dissolved in water twice a day for 45 months.

Group II: Group 2 - PlaceboPlacebo Group1 Intervention

Patients in the placebo group will receive identical effervescent tablets lacking active drug.

Treatment

First Studied

Drug Approval Stage

How many patients have taken this drug

N-acetylcysteine

2008

Completed Phase 4

~1290

Do I qualify?Apply below to find out

Research Highlights

Information in this section is not a recommendation. We encourage patients to speak with their healthcare team when evaluating any treatment decision.

Mechanism Of Action

Side Effect Profile

Prior Approvals

Other Research

Retinitis Pigmentosa (RP) is characterized by the degeneration of rod and cone photoreceptors in the retina, leading to symptoms such as night blindness and peripheral vision loss. One of the treatments being studied for RP is N-acetylcysteine (NAC), which works by reducing oxidative stress—a contributing factor to cone degeneration. By mitigating oxidative damage, NAC aims to slow the progression of photoreceptor loss, potentially preserving vision for a longer period. This is particularly important for RP patients as it addresses one of the underlying mechanisms of the disease, offering hope for improved management and quality of life.