Safety and Efficacy of NPI-001 Tablets for RP Associated With Usher Syndrome

NCT ID: NCT04355689

Last Updated: 2025-12-23

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

ACTIVE_NOT_RECRUITING

Clinical Phase

PHASE1/PHASE2

Total Enrollment

49 participants

Study Classification

INTERVENTIONAL

Study Start Date

2020-09-03

Study Completion Date

2026-04-30

Brief Summary

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This study will examine the safety and efficacy of NPI-001 Tablets as compared to placebo for 24 months in subjects with vision loss due to RP associated with Usher syndrome.

Detailed Description

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This study will examine the safety and efficacy of oral NPI-001 Tablets as compared to oral placebo tablets for 24 months in subjects with vision loss due to RP associated with Usher syndrome.

Conditions

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Usher Syndromes

Keywords

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retinitis pigmentosa Usher vision NPI-001 tablet

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

NPI-001 Tablets versus Placebo
Primary Study Purpose

TREATMENT

Blinding Strategy

QUADRUPLE

Participants Caregivers Investigators Outcome Assessors
Double-masked

Study Groups

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NPI-001

NPI-001 Tablet, 250 mg, BID

Group Type EXPERIMENTAL

NPI-001

Intervention Type DRUG

oral tablet

Placebo

Placebo Tablet, BID

Group Type PLACEBO_COMPARATOR

Placebo

Intervention Type OTHER

Placebo tablets

Interventions

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NPI-001

oral tablet

Intervention Type DRUG

Placebo

Placebo tablets

Intervention Type OTHER

Eligibility Criteria

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Inclusion Criteria

1. Male or female, age ≥18 years.
2. Able to comprehend and willing to sign an informed consent form (ICF) and to adhere to the study protocol.
3. Diagnosed with Usher syndrome.
4. EZ zone with width ≥500 microns, which includes the fovea in each eye at Visit 2, (Screen B).
5. Have at least 20 detectable points on the MAIA grid.
6. On stable dose of medications associated with other conditions for at least one month.
7. Both female participants of childbearing potential and male participants able to father children must have (or have a partner who has) had a bilateral oophorectomy, hysterectomy or bilateral salpingectomy; must abstain from intercourse; or must agree to practice 2 acceptable methods of contraception throughout the course of the study and 4 weeks after the last visit. Acceptable methods of contraception include hormonal contraception (i.e., birth control pills, injected hormones, dermal patch or vaginal ring), intrauterine device, barrier methods (diaphragm, condom) with spermicide, tubal ligation, or vasectomy.

Exclusion Criteria

Ocular:

1. All edges of the EZ area in both eyes cannot be visualized at Visit 2 (Screen B).
2. Concurrent retinal pathologies that result in vision loss or inability to fixate, including but not limited to, choroideremia, retinal vein occlusion, and neovascular age-related macular degeneration.
3. Intraocular surgery within the last two months or capsulotomy within the last month.
4. 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.
5. Unstable fixation during microperimetry in either eye at either screening or baseline visits.

Non-Ocular:
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. Liver or kidney disease, cystic fibrosis, 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).
10. Platelet or hemoglobin values that are below the lower limit of normal at screening (subjects with normal hemoglobin and mean corpuscular volume below the lower limit of normal should have iron studies performed to ensure that they are iron replete before taking part in the study), or neutrophils or white cell count which is above the upper limit of normal.
11. Presence of more than + proteinuria on urinalysis at screening or (confirmed by abnormal albumin creatinine ratio).
12. Presence of hematuria on urinalysis at screening. (If hematuria is detected on urinalysis, then the specimen should be subjected to microscopy, and subject should be excluded if more than 10 X 106 red blood cells/L.) If the subject is a female in whom the hematuria may be due to menses, then the urinalysis can be repeated after a few days.
13. C-reactive protein (CRP) value above 10 mg/L.
14. Subject has a recent history of presence of gross blood in stools.
15. History of known sensitivity to N-acetylcysteine or similar thiol compounds.
16. History of hypersensitivity to any medication or food resulting in systemic symptoms.
17. History of cancer (other than non-melanoma skin cancer) diagnosed or requiring treatment within the past 2 years.
18. 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.
19. Lactating women who are breast-feeding.
20. A potential participant lives in the same household as a current participant in this study.
21. Inability to provide blood samples, including difficulty with venous access.
22. Any reason, in the opinion of the Principal Investigator, the subject should not participate.
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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Foundation Fighting Blindness

OTHER

Sponsor Role collaborator

Nacuity Pharmaceuticals, Inc.

INDUSTRY

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Lee Anderson, MD

Role: STUDY_CHAIR

Nacuity Pharmaceuticals, Inc.

Locations

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Queensland Eye Institute

Brisbane, , Australia

Site Status

CERA

Melbourne, , Australia

Site Status

Lions Eye Institute

Perth, , Australia

Site Status

Sydney Eye Hospital / Save Sight Institute

Sydney, , Australia

Site Status

Countries

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Australia

Other Identifiers

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C-18-04

Identifier Type: -

Identifier Source: org_study_id