Usher SyndromesPhase 1/2SLO RPNCT04355689
Safety and Efficacy of NPI-001 Tablets for RP Associated With Usher Syndrome
A Phase 1/2 study testing NPI-001 in people with Usher Syndromes, run by Nacuity Pharmaceuticals, Inc. at 4 sites in Australia.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Usher Syndromes
- What is being tested?
- NPI-001
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 49 participants
- Where
- 4 sitesAustralia
- Study dates
- 3 Sep 2020to 22 Apr 2026
- Phase
- Phase 1/2
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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.
Who cannot join
- 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.
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- 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.
Trial locations and contacts
4 sites in 1 country.
Australia4 sites
Queensland Eye Institute
Brisbane
CERA
Melbourne
Lions Eye Institute
Perth
Sydney Eye Hospital / Save Sight Institute
Sydney
About this study
Official title: Safety and Efficacy of NPI-001 Tablets Versus Placebo for Treatment of Retinitis Pigmentosa Associated With Usher Syndrome
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.
Read the detailed description
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
- Usher Syndromes
- Being tested
- NPI-001, Placebo
- Keywords
- retinitis pigmentosa Usher vision NPI-001 tablet
- Medical subject headings
- Usher Syndromes
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
NPI-001Drug
oral tablet
PlaceboOther
Placebo tablets
| Study group | Role | What they receive |
|---|---|---|
| NPI-001 | Experimental | NPI-001 Tablet, 250 mg, BID Receives: Drug: NPI-001 |
| Placebo | Placebo comparator | Placebo Tablet, BID Receives: Other: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Evaluate change from baseline for retinal sensitivity assessed by microperimetry of active versus placebo
Evaluate change from baseline for retinal sensitivity assessed by microperimetry of active versus placebo
Measured: 24 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Apr 2020
- Study start3 Sep 2020
- Primary completion20 Jun 2025
- Study completion22 Apr 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Usher SyndromesStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1/2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- NPI-001 Tablets versus Placebo
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 49 participants (actual)
Sponsor and investigators
- Lead sponsor
- Nacuity Pharmaceuticals, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Foundation Fighting Blindness, Nacuity Pharmaceuticals, PTY LTD
- Responsible party
- Sponsor
- Investigators
- Lee Anderson, MD, Study chair, Nacuity Pharmaceuticals, Inc.
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04355689
- Sponsor's protocol ID
- C-18-04
- Acronym
- SLO RP
- Status last verified
- Jun 2026
- First submitted
- 17 Apr 2020
- Last updated
- 1 Jul 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 1 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Safety and Efficacy of NPI-001 Tablets Versus Placebo for Treatment of Retinitis Pigmentosa Associated With Usher Syndrome
- ClinicalTrials.gov ID
- NCT04355689
- Acronym / sponsor ID
- SLO RP / C-18-04
- Conditions
- Usher Syndromes
- Keywords
- retinitis pigmentosa Usher vision NPI-001 tablet
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 49 participants (actual)
- Lead sponsor
- Nacuity Pharmaceuticals, Inc.Industry (pharma, biotech, devices)
- Collaborators
- Foundation Fighting Blindness, Nacuity Pharmaceuticals, PTY LTD
- Study start
- 3 Sep 2020 (actual)
- Primary completion
- 20 Jun 2025 (actual)
- Study completion
- 22 Apr 2026 (actual)
- First posted
- 21 Apr 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- NPI-001 Tablets versus Placebo
| Arm | Type | Receives |
|---|---|---|
| NPI-001 | Experimental | Drug: NPI-001NPI-001 Tablet, 250 mg, BID |
| Placebo | Placebo comparator | Other: PlaceboPlacebo Tablet, BID |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- 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.
Key exclusion criteria (24 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| NPI-001oral tablet | Drug | NPI-001 |
| PlaceboPlacebo tablets | Other | Placebo |
Primary outcome
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
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 Jul 2026.
- Individual participant dataSharing planned: No
Related trials for Usher Syndromes
Active, not recruitingObservational study
Rate of Progression in USH2A-related Retinal Degeneration
Usher Syndrome, Type 2A, Retinitis Pigmentosa 39
RecruitingPhase 1/2
A Study to Investigate the Safety of OpCT-001 in Adults Who Have Primary Photoreceptor Disease (CLARICO)
Primary Photoreceptor Disease, Retinitis Pigmentosa (RP)
RecruitingPhase 3
A 24-Month Trial of NPI-001 for the Preservation of Photoreceptors in Retinitis Pigmentosa Associated With Usher Syndrome
Retinitis Pigmentosa (RP), Usher Syndrome
Not yet recruitingPhase 2
Study to Evaluate the Long-Term Safety of Ultevursen in Participants With Retinitis Pigmentosa (RP) Due to Mutations in Exon 13 of the USH2A Gene
Retinitis Pigmentosa (RP), Usher Syndrome Type 2
Active, not recruitingPhase 2
Study to Evaluate Ultevursen in Subjects With Retinitis Pigmentosa (RP) Due to Mutations in Exon 13 of the USH2A Gene
Retinitis Pigmentosa (RP), Usher Syndrome Type 2
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Lee Anderson, MD study chair
Nacuity Pharmaceuticals, Inc.
4 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing NPI-001 in people with Usher Syndromes, run by Nacuity Pharmaceuticals, Inc. at 4 sites in Australia.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 24 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 1 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 4 sites in Australia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this combined phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Evaluate change from baseline for retinal sensitivity assessed by microperimetry of active versus placebo (time frame: 24 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 1 Jul 2026; AzTrials last refreshed its copy on 7 Nov 2026.