A 24-Month Trial of NPI-001 for the Preservation of Photoreceptors in Retinitis Pigmentosa Associated With Usher Syndrome

NCT07710196 | Not Yet Recruiting Phase 3 FDA Drug

• 1 other identifier: C-26-01
• Study Type: interventional
• Target: 80
• Locations: 0 countries
• Sites: N/A

Brief Summary

The goal of this clinical trial is to learn if NPI-001 works to prevent progression of retinitis pigmentosa in adults diagnosed with Usher syndrome. It will also provide information about the safety of NPI-001. The main questions it aims to answer are: Does NPI-001 slow down the loss of photoreceptors? What medical problems do participants have when taking NPI-001? Researchers will compare NPI-001 to a placebo (a look-alike substance that contains no drug) to see if NPI-001 works to preserve vision. Participants will: Take NPI-001 or a placebo twice a day, every day for 24 months and visit the clinic 9 times for checkups and tests.

Conditions

Retinitis Pigmentosa (RP); Usher Syndrome

Outcome Measures

Primary Outcomes (1)

• Ellipsoid Zone Area

  24 months

Study Arms (2)

Placebo

PLACEBO COMPARATOR

Oral Placebo Tablet

Drug: Placebo

NPI-001

EXPERIMENTAL

Oral N-Acetyl Cysteine Amide Tablet

Drug: NPI-001

Interventions

Placebo DRUG

Oral placebo tablet

Placebo

NPI-001 DRUG

Oral n-acetyl cysteine amide tablet

NPI-001

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Able to comprehend and willing to sign an informed consent form (OCF) and adhere to the study protocol.
• Diagnosed with RP associated with Usher syndrome.
• EZ width ≥ 500 microns, which includes the fovea in each eye at Visit 1.
• All edges of the EZ area in both eyes can be visualized at Visit 1 (Screening).
• 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).
• On stable dose of medications associated with other conditions for at least one month.
• Willing to use contraception during study (for anyone of childbearing potential).

You may not qualify if:

• Concurrent retinal pathologies that result in vision loss or inability to fixate.
• Intraocular surgery within the last two months or capsulotomy within the last month.
• 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.
• Likely to require cataract surgery within the next 12 months.
• Unstable fixation during microperimetry in either eye at either Screening or Baseline visits.
• Use of any other investigational new drug, or participation in another clinical trial within 12 weeks before the start of study treatment.
• 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.
• 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.
• 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.
• Platelet or hemoglobin values \< 100 at screening.
• History of known sensitivity to N-acetylcysteine or similar thiol compounds or any ingredients of NPI-001.
• History of hypersensitivity to any medication or food resulting in systemic symptoms.
• History of cancer (other than non-melanoma skin cancer) diagnosed or requiring treatment within the past 2 years.
• 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.
• Lactating women who are breast-feeding.

Sponsors & Collaborators

• Nacuity Pharmaceuticals, Inc.: lead
• Foundation Fighting Blindness: collaborator

MeSH Terms

Conditions

Retinitis Pigmentosa; Usher Syndromes

Condition Hierarchy (Ancestors)

Eye Diseases, Hereditary; Eye Diseases; Retinal Dystrophies; Retinal Degeneration; Retinal Diseases; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Deaf-Blind Disorders; Deafness; Hearing Loss; Hearing Disorders; Ear Diseases; Otorhinolaryngologic Diseases; Hearing Loss, Sensorineural; Sensation Disorders; Neurologic Manifestations; Nervous System Diseases; Blindness; Vision Disorders; Abnormalities, Multiple; Congenital Abnormalities; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Central Study Contacts

Nacuity Pharmaceuticals

CONTACT

+1-817-336-3000; info@nacuity.com

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 13, 2026
• First Posted: July 17, 2026
• Study Start: August 1, 2026
• Primary Completion (Estimated): February 1, 2029
• Study Completion (Estimated): February 1, 2029
• Last Updated: July 17, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share