Retinitis PigmentosaPhase 1NCT00065455
Investigating the Effect of Vitamin A Supplementation on Retinitis Pigmentosa
A Phase 1 study testing Vitamin A in people with Retinitis Pigmentosa, run by National Eye Institute (NEI) at 1 site in United States.
Trial summary
Retinitis pigmentosa (RP) is a collective term for a group of inherited retinal dystrophies that are a major cause of irreversible blindness. RP of some type occurs in approximately 1 out of 3500 persons in the United States(1). Gene mutations are responsible for the majority of RP. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Retinitis Pigmentosa
- What is being tested?
- Vitamin A
- How many people
- 11 participants
- Where
- 1 siteUnited States
- Study dates
- 17 Jul 2003to 6 May 2009
- Phase
- Phase 1
- 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
- All participants must meet the following criteria to participate in the study.
- Men and women age 18 years of age and older. (Children will be excluded since there is a higher incidence of vitamin A toxicity in the pediatric population.)
- Diagnoses of typical RP of all genetic subtypes (simplex, autosomal dominant, autosomal recessive, and X-linked), as determined primarily by abnormally reduced ERG rod response amplitudes that are relatively more affected than cone ERG amplitudes.
- Mutation in the RHO1 gene as determined by genotyping.
- Participants in whom flicker ERG can be measured reliably (standard flicker ERG amplitude greater than 2 microV).
- Willingness to use contraception for the duration of the study.
- Understood and signed consent.
Who cannot join
- Participants with the following conditions will be excluded from study.
- Participants with syndromic RP (i.e., Ushers syndrome).
- Have abnormal liver function (greater than ULN ALT, AST, Alkaline Phosphate, or Total Bilirubin).
- Hematocrit greater than 1.5 x ULN
- Have abnormal kidney function (greater than1.5 mg/dL serum creatinine).
- Currently or has taken greater than 15,000 IU/day vitamin A supplementation within 6 months of the first screening visit.
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- Is pregnant or lactating (due to evidence that sugests excessive intake of vitamin A could be tertogenic in humans and affect the content of breast milk).
- Currently or has taken greater than 400 IU/day of vitamin E supplementation within 6 months of enrollment.
- Vitamin A serum level exceeding 150 microg/dL.
Trial locations and contacts
1 site in 1 country.
United States1 site
National Institutes of Health Clinical Center, 9000 Rockville Pike
Bethesda, Maryland, 20892
About this study
Official title: Pilot Study on the Effect of Vitamin A Supplementation on Cone Function in Retinitis Pigmentosa
Retinitis pigmentosa (RP) is a collective term for a group of inherited retinal dystrophies that are a major cause of irreversible blindness. RP of some type occurs in approximately 1 out of 3500 persons in the United States(1). Gene mutations are responsible for the majority of RP. To date, mutations have been identified in 30 different genes linked to RP(2). The visual prognosis of RP is poor, since the gradual but relentless visual field loss leads eventually to some degree of blindness(3). Although no effective treatment for RP has been identified, participants supplemented with a daily oral dose of 15,000 IU vitamin A palmitate have shown, on average, a slower rate of deterioration of retinal function when the intervention is continued over several years(4). The purpose of this research is to determine whether administration of high oral doses of vitamin A can acutely improve cone photoreceptor function in RP participants as measured by electroretinography (ERG). In this interventional, non-randomized, prospective, pilot study, 5 participants will receive a daily oral dose of 50,000 IU of vitamin A palmitate for 4 weeks, followed by a maintenance dose of 15,000 IU daily for the subsequent 2 weeks. The primary efficacy outcome is a relative percentage change in ERG response amplitude subsequent to vitamin A supplementation. A secondary efficacy outcome is a relative percentage change in implicit time from pre- to post- vitamin A supplementation, with improvement specified as a shorter response implicit time. Other secondary outcomes will be improvements in visual field (Humphery, 10-2; sum of thresholds). Safety outcomes include visual fields, ETDRS visual acuity, intraocular pressure, serum vitamin A level and liver function tests.
Read the detailed description
Retinitis pigmentosa (RP) is a collective term for a group of inherited retinal dystrophies that are a major cause of irreversible blindness. RP of some type occurs in approximately 1 out of 3500 persons in the United States. Gene mutations are responsible for the majority of RP. To date, mutations have been identified in 30 different genes linked to RP. The visual prognosis of RP is poor, since the gradual but relentless visual field loss leads eventually to some degree of blindness. Although no effective treatment for RP has been identified, participants supplemented with a daily oral dose of 15,000 IU vitamin A palmitate have shown, on average, a slower rate of deterioration of retinal function when the intervention is continued over several years. The purpose of this research is to determine whether administration of high oral doses of vitamin A can acutely improve cone photoreceptor function in RP participants as measured by electroretinography (ERG). In this interventional, non-randomized, prospective, pilot study, 10 participants (five with the RHO1 gene mutation and five without the mutation) will receive a daily oral dose of 50,000 IU of vitamin A palmitate for 4 weeks, followed by a maintenance dose of 15,000 IU daily for the subsequent 2 weeks. The primary efficacy outcome is a relative percentage change in ERG response amplitude subsequent to vitamin A supplementation. A secondary efficacy outcome is a relative percentage change in implicit time from pre- to post- vitamin A supplementation, with improvement specified as a shorter response implicit time. Other secondary outcomes will be improvements in visual field (Humphrey 10-2; sum of thresholds). Safety outcomes include visual fields, ETDRS visual acuity, intraocular pressure, serum vitamin A level and liver function tests.
- Conditions
- Retinitis Pigmentosa
- Being tested
- Vitamin A
- Keywords
- Retinitis Pigmentosa, Vitamin A, ERG, RP
- Medical subject headings
- Retinitis Pigmentosa
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Vitamin ADrug
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Jul 2003 (estimated)
- Study start17 Jul 2003
- Study completion6 May 2009
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Retinitis PigmentosaStudies 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
- Primary purpose
- Treatment
- Enrolment
- 11 participants
Sponsor and investigators
- Lead sponsor
- National Eye Institute (NEI)
- Sponsor type
- US National Institutes of Health
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00065455
- Sponsor's protocol ID
- 030255
- Other IDs
- 03-EI-0255
- Status last verified
- 6 May 2009
- First submitted
- 23 Jul 2003
- Last updated
- 2 Jul 2017
- Results posted
- No
Publications
Phelan JK, Bok D. A brief review of retinitis pigmentosa and the identified retinitis pigmentosa genes. Mol Vis. 2000 Jul 8;6:116-24.
PubMed 10889272Milam AH, Li ZY, Fariss RN. Histopathology of the human retina in retinitis pigmentosa. Prog Retin Eye Res. 1998 Apr;17(2):175-205. doi: 10.1016/s1350-9462(97)00012-8.
PubMed 9695792Huang PC, Gaitan AE, Hao Y, Petters RM, Wong F. Cellular interactions implicated in the mechanism of photoreceptor degeneration in transgenic mice expressing a mutant rhodopsin gene. Proc Natl Acad Sci U S A. 1993 Sep 15;90(18):8484-8. doi: 10.1073/pnas.90.18.8484.
PubMed 8378322
Study at a glance
From the registry record, last updated by the sponsor on 2 Jul 2017. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Pilot Study on the Effect of Vitamin A Supplementation on Cone Function in Retinitis Pigmentosa
- ClinicalTrials.gov ID
- NCT00065455
- Acronym / sponsor ID
- 030255
- Conditions
- Retinitis Pigmentosa
- Keywords
- Retinitis Pigmentosa, Vitamin A, ERG, RP
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 11 participants
- Lead sponsor
- National Eye Institute (NEI)US National Institutes of Health
- Study start
- 17 Jul 2003
- Study completion
- 6 May 2009
- First posted
- 24 Jul 2003 (estimated)
- 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.
Retinitis pigmentosa (RP) is a collective term for a group of inherited retinal dystrophies that are a major cause of irreversible blindness. RP of some type occurs in approximately 1 out of 3500 persons in the United States(1). Gene mutations are responsible for the majority of RP. To date, mutations have been identified in 30 different genes linked to RP(2). The visual prognosis of RP is poor, since the gradual but relentless visual field loss leads eventually to some degree of blindness(3). Although no effective treatment for RP has been identified, participants supplemented with a daily oral dose of 15,000 IU vitamin A palmitate have shown, on average, a slower rate of deterioration of retinal function when the intervention is continued over several years(4). The purpose of this research is to determine whether administration of high oral doses of vitamin A can acutely improve cone photoreceptor function in RP participants as measured by electroretinography (ERG). In this interventional, non-randomized, prospective, pilot study, 5 participants will receive a daily oral dose of 50,000 IU of vitamin A palmitate for 4 weeks, followed by a maintenance dose of 15,000 IU daily for the subsequent 2 weeks. The primary efficacy outcome is a relative percentage change in ERG response amplitude subsequent to vitamin A supplementation. A secondary efficacy outcome is a relative percentage change in implicit time from pre- to post- vitamin A supplementation, with improvement specified as a shorter response implicit time. Other secondary outcomes will be improvements in visual field (Humphery, 10-2; sum of thresholds). Safety outcomes include visual fields, ETDRS visual acuity, intraocular pressure, serum vitamin A level and liver function tests.
Detailed description
Retinitis pigmentosa (RP) is a collective term for a group of inherited retinal dystrophies that are a major cause of irreversible blindness. RP of some type occurs in approximately 1 out of 3500 persons in the United States. Gene mutations are responsible for the majority of RP. To date, mutations have been identified in 30 different genes linked to RP. The visual prognosis of RP is poor, since the gradual but relentless visual field loss leads eventually to some degree of blindness. Although no effective treatment for RP has been identified, participants supplemented with a daily oral dose of 15,000 IU vitamin A palmitate have shown, on average, a slower rate of deterioration of retinal function when the intervention is continued over several years. The purpose of this research is to determine whether administration of high oral doses of vitamin A can acutely improve cone photoreceptor function in RP participants as measured by electroretinography (ERG). In this interventional, non-randomized, prospective, pilot study, 10 participants (five with the RHO1 gene mutation and five without the mutation) will receive a daily oral dose of 50,000 IU of vitamin A palmitate for 4 weeks, followed by a maintenance dose of 15,000 IU daily for the subsequent 2 weeks. The primary efficacy outcome is a relative percentage change in ERG response amplitude subsequent to vitamin A supplementation. A secondary efficacy outcome is a relative percentage change in implicit time from pre- to post- vitamin A supplementation, with improvement specified as a shorter response implicit time. Other secondary outcomes will be improvements in visual field (Humphrey 10-2; sum of thresholds). Safety outcomes include visual fields, ETDRS visual acuity, intraocular pressure, serum vitamin A level and liver function tests.
Study design
- Primary purpose
- Treatment
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- All participants must meet the following criteria to participate in the study.
- Men and women age 18 years of age and older. (Children will be excluded since there is a higher incidence of vitamin A toxicity in the pediatric population.)
- Diagnoses of typical RP of all genetic subtypes (simplex, autosomal dominant, autosomal recessive, and X-linked), as determined primarily by abnormally reduced ERG rod response amplitudes that are relatively more affected than cone ERG amplitudes.
- Mutation in the RHO1 gene as determined by genotyping.
- Participants in whom flicker ERG can be measured reliably (standard flicker ERG amplitude greater than 2 microV).
Key exclusion criteria (9 listed)
- Participants with the following conditions will be excluded from study.
- Participants with syndromic RP (i.e., Ushers syndrome).
- Have abnormal liver function (greater than ULN ALT, AST, Alkaline Phosphate, or Total Bilirubin).
- Hematocrit greater than 1.5 x ULN
- Have abnormal kidney function (greater than1.5 mg/dL serum creatinine).
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 |
|---|---|---|
| Vitamin A | Drug | – |
Primary outcome
Not reported in the source record.
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 2 Jul 2017.
- Background: PubMed 10889272Phelan JK, Bok D. A brief review of retinitis pigmentosa and the identified retinitis pigmentosa genes. Mol Vis. 2000 Jul 8;6:116-24.
- Background: PubMed 9695792Milam AH, Li ZY, Fariss RN. Histopathology of the human retina in retinitis pigmentosa. Prog Retin Eye Res. 1998 Apr;17(2):175-205. doi: 10.1016/s1350-9462(97)00012-8.
- Background: PubMed 8378322Huang PC, Gaitan AE, Hao Y, Petters RM, Wong F. Cellular interactions implicated in the mechanism of photoreceptor degeneration in transgenic mice expressing a mutant rhodopsin gene. Proc Natl Acad Sci U S A. 1993 Sep 15;90(18):8484-8. doi: 10.1073/pnas.90.18.8484.
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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.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Vitamin A in people with Retinitis Pigmentosa, run by National Eye Institute (NEI) 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 7 inclusion and 9 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 2 Jul 2017. 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.
What does this 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.
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.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT00065455, which also lists 3 linked publications.
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 2 Jul 2017.