Safety and Efficacy of NPI-001 Tablets for RP Associated With Usher Syndrome (SLO RP)
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The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. |
ClinicalTrials.gov Identifier: NCT04355689 |
Recruitment Status :
Recruiting
First Posted : April 21, 2020
Last Update Posted : November 18, 2022
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Condition or disease | Intervention/treatment | Phase |
---|---|---|
Usher Syndromes | Drug: NPI-001 Other: Placebo | Phase 1 Phase 2 |
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 48 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Intervention Model Description: | NPI-001 Tablets versus Placebo |
Masking: | Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor) |
Masking Description: | Double-masked |
Primary Purpose: | Treatment |
Official Title: | Safety and Efficacy of NPI-001 Tablets Versus Placebo for Treatment of Retinitis Pigmentosa Associated With Usher Syndrome |
Actual Study Start Date : | September 3, 2020 |
Estimated Primary Completion Date : | January 2025 |
Estimated Study Completion Date : | January 2025 |

Arm | Intervention/treatment |
---|---|
Experimental: NPI-001
NPI-001 Tablet, 250 mg, BID
|
Drug: NPI-001
oral tablet |
Placebo Comparator: Placebo
Placebo Tablet, BID
|
Other: Placebo
Placebo tablets |
- Evaluate change from baseline for retinal sensitivity assessed by microperimetry of active versus placebo [ Time Frame: 24 months ]Evaluate change from baseline for retinal sensitivity assessed by microperimetry of active versus placebo

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Male or female, age ≥18 years.
- Able to comprehend and willing to sign an informed consent form (ICF) and to adhere to the study protocol.
- Diagnosed with Usher syndrome.
- EZ zone with width ≥500 microns, which includes the fovea in each eye at Visit 2, (Screen B).
- Have at least 20 detectable points on the MAIA grid.
- On stable dose of medications associated with other conditions for at least one month.
- 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:
- All edges of the EZ area in both eyes cannot be visualized at Visit 2 (Screen B).
- 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.
- Intraocular surgery within the last two months or capsulotomy within the last month.
- 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.
-
Unstable fixation during microperimetry in either eye at either screening or baseline visits.
Non-Ocular:
- 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.
- 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.
- Suspected liver dysfunction determined by having alanine aminotransferase (ALT), aspartate aminotransferase (AST), or bilirubin values > 1.5 X the upper limit of normal (ULN).
- 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.
- Presence of more than + proteinuria on urinalysis at screening or (confirmed by abnormal albumin creatinine ratio).
- 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.
- C-reactive protein (CRP) value above 10 mg/L.
- Subject has a recent history of presence of gross blood in stools.
- History of known sensitivity to N-acetylcysteine or similar thiol compounds.
- 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.
- A potential participant lives in the same household as a current participant in this study.
- Inability to provide blood samples, including difficulty with venous access.
- Any reason, in the opinion of the Principal Investigator, the subject should not participate.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04355689
Contact: Jami Kern, PhD | +1-817-336-3000 | info@nacuity.com | |
Contact: G. Michael Wall, PhD | +1-817-336-3000 | info@nacuity.com |
Australia | |
Queensland Eye Institute | Recruiting |
Brisbane, Australia | |
Contact: Research Manager | |
CERA | Recruiting |
Melbourne, Australia | |
Contact: Research Manager | |
Lions Eye Institute | Recruiting |
Perth, Australia | |
Contact: Research Manager | |
Sydney Eye Hospital / Save Sight Institute | Recruiting |
Sydney, Australia | |
Contact: Research Manager |
Study Chair: | Lee Anderson, MD | Nacuity Pharmaceuticals, Inc. |
Responsible Party: | Nacuity Pharmaceuticals, Inc. |
ClinicalTrials.gov Identifier: | NCT04355689 |
Other Study ID Numbers: |
C-18-04 |
First Posted: | April 21, 2020 Key Record Dates |
Last Update Posted: | November 18, 2022 |
Last Verified: | November 2022 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Studies a U.S. FDA-regulated Drug Product: | No |
Studies a U.S. FDA-regulated Device Product: | No |
retinitis pigmentosa Usher vision NPI-001 tablet |
Usher Syndromes Retinitis Pigmentosa Syndrome Disease Pathologic Processes Retinal Diseases Eye Diseases Eye Diseases, Hereditary Retinal Dystrophies Retinal Degeneration Genetic Diseases, Inborn 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 |