Clinical trial Recruiting at 1 site Phase 3 Interventional Ages 18 and up

NPI-001 for preserving photoreceptors in RP with Usher syndrome

Official title: A 24-Month, Randomized, Double-Masked, Placebo-Controlled Trial of NPI-001 for the Preservation of Photoreceptors in Retinitis PigmentosaAssociated With Usher Syndrome

Run by Nacuity Pharmaceuticals, Inc. · NCT07710196 · Data updated 2026-11-12

This trial tests whether NPI-001 can slow vision loss in adults with RP linked to Usher syndrome, compared with a placebo over 24 months.

More Retinitis Pigmentosa (RP) trials

Quick facts

PhasePhase 3
Study typeInterventional
Ages18 Years and up
SexAll
Enrollment80 (estimated)
SponsorNacuity Pharmaceuticals, Inc.
Industry-sponsored
Locations1 site (Dallas, Texas)
StatusRecruiting
StartedOctober 23, 2026
Main results expectedApril 2029
Study endsApril 2029
Registry record updatedNovember 10, 2026
Trial IDNCT07710196 on ClinicalTrials.gov

Is this trial a fit for you?

Likely a good fit

Adults with RP associated with Usher syndrome who meet EZ width and MAIA criteria and are willing to use contraception if applicable.

Probably not a fit

Individuals with other retinal conditions, recent eye surgery, or factors affecting fixation may not experience benefit.

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This is a phase 3, randomized, placebo-controlled trial evaluating NPI-001 for preserving photoreceptors in adults with RP associated with Usher syndrome. Participants will take either NPI-001 or placebo twice daily for 24 months and undergo nine clinic visits for safety and efficacy assessments. Key measures include photoreceptor preservation and safety outcomes. Eligible individuals must have RP with Usher syndrome, sufficient EZ width, detectable MAIA points, and stable concurrent medications. Exclusion criteria include other retinal diseases, recent intraocular surgery, and conditions that could affect fixation or vision.

Why it matters

Potential benefit: If successful, participants may experience slower vision loss and better preservation of photoreceptors.

How similar studies have gone: Prior research in similar retinal preservation approaches has shown mixed but promising signals; this trial represents a later-stage, rigorous test in a well-defined population.

Who can join: the full rules

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. Able to comprehend and willing to sign an informed consent form (OCF) and adhere to the study protocol.
2. Diagnosed with RP associated with Usher syndrome.
3. EZ width ≥ 500 microns, which includes the fovea in each eye at Visit 1.
4. All edges of the EZ area in both eyes can be visualized at Visit 1 (Screening).
5. Have at least 20 detectable points on the MAIA grid in at least one eye at the Screening and Baseline visits (same eye for both visits).
6. On stable dose of medications associated with other conditions for at least one month.
7. Willing to use contraception during study (for anyone of childbearing potential).

Exclusion Criteria:

1. Concurrent retinal pathologies that result in vision loss or inability to fixate.
2. Intraocular surgery within the last two months or capsulotomy within the last month.
3. Current or history of uveitis, Coat's disease, diabetic retinopathy, glaucoma, herpes simplex of the eye, or currently has a cataract that prevents visualization of the posterior pole.
4. Likely to require cataract surgery within the next 12 months.
5. Unstable fixation during microperimetry in either eye at either Screening or Baseline visits.
6. Use of any other investigational new drug, or participation in another clinical trial within 12 weeks before the start of study treatment.
7. Use of N-acetylcysteine containing products in the previous 30 days prior to the baseline visit or unwilling to refrain from such supplements for the duration of the study.
8. Chronic liver or kidney disease, cystic fibrosis, severe asthma, or chronic obstructive pulmonary disease (COPD), history of thrombocytopenia not due to a reversible cause, or other blood dyscrasia.
9. Suspected liver dysfunction determined by having alanine aminotransferase (ALT), aspartate aminotransferase (AST), or bilirubin values \> 1.5 X the upper limit of normal (ULN) at screening.
10. Platelet or hemoglobin values \< 100 at screening.
11. History of known sensitivity to N-acetylcysteine or similar thiol compounds or any ingredients of NPI-001.
12. History of hypersensitivity to any medication or food resulting in systemic symptoms.
13. History of cancer (other than non-melanoma skin cancer) diagnosed or requiring treatment within the past 2 years.
14. Pregnant women or women planning to become pregnant in the next 25 months or men with partners planning to become pregnant in the next 25 months.
15. Lactating women who are breast-feeding.
16. Potential participant lives in the same household as a current participant in this study.
17. Subjects who are unwilling or unable to refrain from donation of blood from 30 days prior to Screening, plasma from 2 weeks prior to Screening, or platelets from 6 weeks prior to Screening until 56 days following the last study drug dose administered.
18. Inability to provide blood samples, including difficulty with venous access.
19. Any reason, in the opinion of the Principal Investigator, the participant should not participate.

Where it's running

  • Retina Foundation of the Southwest
    Dallas, Texas, United States
    Recruiting

Study contacts

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

How to take part

  1. Review the eligibility criteria above with your treating physician.
  2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
  3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.
Last reviewed 2026-11-14 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.