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ChoroideremiaDARCNCT05045703

The Dark-Adapted Retinal Function Response in Choroideremia (DARC) Study

A study testing Vitamin A palmitate in people with Choroideremia, run by Duke University at 1 site in United States.

Withdrawn

Withdrawn. The study stopped before anyone enrolled.

Official record
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Trial summary

Choroideremia (CHM) is an inherited retinal disorder that causes progressive vision loss, ultimately leading to complete blindness. The first symptom is generally night blindness, although, to date, little is known about the extent, type, pattern, and progression of dark-adapted visual function measures in CHM… Read more about this study

Who is it for?
Ages 15 years and older, men onlyHealthy volunteers can take part
Conditions the study is for
Choroideremia
What is being tested?
Vitamin A palmitate
Could I receive a placebo?
No, everyone receives an active treatment
How many people
0 participants
Where
1 siteUnited States
Study dates
May 2023to May 2024
Phase
Interventional
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 15 years and older
  • Men only
  • Healthy volunteers accepted
  • Child, Adult, Older adult

Who may be able to join

  • males at least 15 years of age with molecularly-confirmed diagnosis of choroideremia

Who cannot join

  • inability to participate in visual field testing reliably and reproducibly

Trial locations and contacts

1 site in 1 country.

United States1 site

  • Duke Eye Center

    Durham, North Carolina, 27710

Other trials in United States

About this study

Official title: Characterization of Night Vision Impairment in Choroideremia and Short-Term Vitamin A Supplementation: The Dark-Adapted Retinal Function Response in Choroideremia (DARC) Study

Choroideremia (CHM) is an inherited retinal disorder that causes progressive vision loss, ultimately leading to complete blindness. The first symptom is generally night blindness, although, to date, little is known about the extent, type, pattern, and progression of dark-adapted visual function measures in CHM patients. We hypothesize that one of the key events causing night blindness in CHM is deficiency in the chromophore of the rod visual pigment, rhodopsin. We propose that this deficiency is at least in part due to inadequate delivery of vitamin A (all-trans-retinol) to the photoreceptors (PRs) from the ailing retinal pigment epithelium (RPE), characteristic of CHM. We hypothesize that increased availability of vitamin A would potentiate its entry into the RPE-mediated visual cycle, ultimately enabling delivery to the PRs. This would in turn allow rods to perform better by partially overcoming the RPE damage and the impaired chromophore recycling that we postulate exists in CHM. The goals of this proposal are: (1) to test the hypothesis that oral vitamin A supplementation can improve night time and peripheral vision in CHM patients, and (2) to provide detailed characterization of dark-adapted visual function outcome measures to guide interventional CHM trials.

Conditions
Choroideremia
Being tested
Vitamin A palmitate
Keywords
vitamin A, night vision
Medical subject headings
Choroideremia

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Vitamin A palmitateDietary supplement

    Vitamin A palmitate, 15,000 IU daily for 4 months

Study groups in NCT05045703
Study groupRoleWhat they receive
Vitamin A palmitateExperimentalVitamin A palmitate, 15,000 IU daily for 4 months
Receives: Dietary Supplement: Vitamin A palmitate

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change in dark-adapted full-field visual field sensitivity

    Dark-adapted full-field visual field sensitivity will be measured using the Medmont dark-adapted chromatic perimeter.

    Measured: Measurements at 0, 4, and 8 months. The 0 months measurement will serve as the baseline. The 4 month measurement will assess change due to vitamin A supplementation. The 8 month measurement will assess reversal of this change following washout period

  2. Change in dark-adapted macular visual field sensitivity

    Dark-adapted macular visual field sensitivity will be measured using the Medmont dark-adapted chromatic perimeter.

    Measured: Measurements at 0, 4, and 8 months. The 0 months measurement will serve as the baseline. The 4 month measurement will assess change due to vitamin A supplementation. The 8 month measurement will assess reversal of this change following washout period

  3. Change in dark adaptometry

    Dark adaptometry will be measured using the MacuLogix AdaptDx dark adaptometer.

    Measured: Measurements at 0, 4, and 8 months. The 0 months measurement will serve as the baseline. The 4 month measurement will assess change due to vitamin A supplementation. The 8 month measurement will assess reversal of this change following washout period

Secondary outcomes (10)

  1. Change in best corrected visual acuity

    Best corrected visual acuity will be measured using the ETDRS chart

    Measured: Measurements at 0, 4, and 8 months. The 0 months measurement will serve as the baseline. The 4 month measurement will assess change due to vitamin A supplementation. The 8 month measurement will assess reversal of this change following washout period

  2. Change in low luminance visual acuity

    Low luminance visual acuity will be measured using the ETDRS chart in low luminance conditions

    Measured: Measurements at 0, 4, and 8 months. The 0 months measurement will serve as the baseline. The 4 month measurement will assess change due to vitamin A supplementation. The 8 month measurement will assess reversal of this change following washout period

  3. Change in full-field light-adapted visual field sensitivity

    Light-adapted full-field visual field sensitivity will be measured using the Octopus 172-point GATE full-field semi-automated kinetic perimetry (SKP)

    Measured: Measurements at 0, 4, and 8 months. The 0 months measurement will serve as the baseline. The 4 month measurement will assess change due to vitamin A supplementation. The 8 month measurement will assess reversal of this change following washout period

  4. Change in light-adapted macular visual field sensitivity

    Light-adapted macular visual field sensitivity will be measured using the Centervue MAIA confocal macular microperimeter

    Measured: Measurements at 0, 4, and 8 months. The 0 months measurement will serve as the baseline. The 4 month measurement will assess change due to vitamin A supplementation. The 8 month measurement will assess reversal of this change following washout period

  5. Change in retinal pigmented epithelium (RPE) atrophy by optical coherence tomography

    Retinal pigmented epithelium (RPE) atrophy will be measured using the Spectralis macular spectral domain optical coherence tomography (SD-OCT) with and without enhanced depth imaging (EDI)

    Measured: Measurements at 0, 4, and 8 months. The 0 months measurement will serve as the baseline. The 4 month measurement will assess change due to vitamin A supplementation. The 8 month measurement will assess reversal of this change following washout period

  6. Change in retinal pigmented epithelium (RPE) atrophy by color photography

    Retinal pigmented epithelium (RPE) atrophy will be measured using the Optos wide-field color fundus photography (WF-CFP)

    Measured: Measurements at 0, 4, and 8 months. The 0 months measurement will serve as the baseline. The 4 month measurement will assess change due to vitamin A supplementation. The 8 month measurement will assess reversal of this change following washout period

  7. Change in retinal pigmented epithelium (RPE) atrophy by fundus autofluorescence

    Retinal pigmented epithelium (RPE) atrophy will be measured using the Optos wide-field fundus auto-fluorescence (WF-FAF)

    Measured: Measurements at 0, 4, and 8 months. The 0 months measurement will serve as the baseline. The 4 month measurement will assess change due to vitamin A supplementation. The 8 month measurement will assess reversal of this change following washout period

  8. Change in retinal pigmented epithelium (RPE) atrophy by fundoscopy

    Retinal pigmented epithelium (RPE) atrophy will be assessed by slit lamp biomicroscopy

    Measured: Measurements at 0, 4, and 8 months. The 0 months measurement will serve as the baseline. The 4 month measurement will assess change due to vitamin A supplementation. The 8 month measurement will assess reversal of this change following washout period

  9. Change in liver function

    Liver function profile will be measured by laboratory using participant serum samples

    Measured: Measurements at 0, 4, and 8 months

  10. Change in serum vitamin A levels

    Serum vitamin A levels will be measured by laboratory using participant serum samples

    Measured: Measurements at 0, 4, and 8 months. The 0 months measurement will serve as the baseline. The 4 month measurement will assess change due to vitamin A supplementation. The 8 month measurement will assess reversal of this change following washout period

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted16 Sep 2021
  2. Study startMay 2023 (estimated)
  3. Primary completionMar 2024 (estimated)
  4. Study completionMay 2024 (estimated)

Why it stopped: PI left the institution

Resources

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 N/A
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
0 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05045703
Sponsor's protocol ID
Pro00108901
Acronym
DARC
Status last verified
Jun 2023
First submitted
7 Sep 2021
Last updated
29 Jun 2023
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A study testing Vitamin A palmitate in people with Choroideremia, run by Duke University at 1 site in United States.

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 1 inclusion and 1 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: withdrawn, as of the sponsor's last update on 29 Jun 2023. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. 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. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study was withdrawn before enrolling participants, so there are no results.

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?

Change in dark-adapted full-field visual field sensitivity (time frame: Measurements at 0, 4, and 8 months. The 0 months measurement will serve as the baseline. The 4 month measurement will assess change due to vitamin A supplementation. The 8 month measurement will assess reversal of this change following washout period). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05045703.

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 29 Jun 2023.

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