DHA and X-Linked Retinitis Pigmentosa

This study is ongoing, but not recruiting participants.
Sponsor:
Collaborators:
Foundation Fighting Blindness
DSM Nutritional Products, Inc.
Information provided by (Responsible Party):
Dennis Hoffman, Retina Foundation of the Southwest
ClinicalTrials.gov Identifier:
NCT00100230
First received: December 27, 2004
Last updated: October 10, 2013
Last verified: October 2013
  Purpose

Purpose:

Retinitis pigmentosa (RP) is characterized by progressive loss of visual function due to specific genetic mutations. This trial is focused on patients with one of the most severe forms of the disease, X-linked inherited RP (XLRP). This disease is characterized by early onset (typically loss of night vision as a child) followed by loss of peripheral vision as a teenager and young adult. There is no male-to-male transmission of the disease in the family.

There is no cure for RP and treatment options are limited. Two clinical trials have not found a benefit from nutritional supplementation with the long-chain polyunsaturated fatty acid, docosahexaenoic acid (DHA), at low daily doses although there is evidence that it slows disease progression in certain instances. In this clinical trial, we propose that a high dose nutritional DHA supplement will slow the loss of visual function and preserve usable vision in patients with XLRP.

This study is a 4-year placebo-controlled randomized clinical trial meaning that patients have a 50-50 chance of receiving placebo or experimental treatment. A total of 66 patients will be enrolled; 33 will receive placebo and 33 will receive the treatment. Entry criteria include diagnosis of XLRP by an ophthalmologist, age 7 to 32 years, male, sufficient visual function such that disease progression can be followed for the entire duration of the trial, and a willingness to visit the testing site (Dallas, TX) once a year.

Annual visual function testing includes ETDRS visual acuity, full-field and multifocal electroretinography (ERG), static peripheral visual fields, and fundus photography. Cone ERG function is the primary outcome measure.

Funding Source - FDA OOPD


Condition Intervention Phase
Retinitis Pigmentosa
X-linked Genetic Diseases
Drug: docosahexaenoic acid OR corn/soy oil placebo
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Prevention
Official Title: Investigation of Effectiveness and Safety of High Dose Docosahexaenoic Acid (DHA) in X-Linked Retinitis Pigmentosa

Resource links provided by NLM:


Further study details as provided by Retina Foundation of the Southwest:

Primary Outcome Measures:
  • rate of loss of 31 hertz cone electroretinographic function [ Time Frame: 4 years ] [ Designated as safety issue: Yes ]
    Hypothesis #1: Elevation of red blood cell-docosahexaenoic acid levels will slow the progressive loss of 31 hertz cone electroretinographic response in this 4-year trial.


Secondary Outcome Measures:
  • rate of loss of visual function [ Time Frame: 4 years ] [ Designated as safety issue: Yes ]
    Hypothesis #2: Elevation of red blood cell-docosahexaenoic acid levels will slow the progressive loss of visual function as measured by rod electroretinographic responses, maximal electroretinographic responses, final dark-adapted thresholds, visual acuity and visual field sensitivity in this 4-year trial.


Estimated Enrollment: 66
Study Start Date: September 2004
Estimated Study Completion Date: March 2014
Primary Completion Date: May 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 1.
Oral Docosahexaenoic acid, dosage based on body weight
Drug: docosahexaenoic acid OR corn/soy oil placebo
daily intake of DHA based on body weight or corn/soy oil placebo(oil not containing DHA; 4 year trial
Other Names:
  • DHA; omega-3 fatty acid
  • OR RANDOMIZED TO corn/soy oil placebo
Placebo Comparator: 2
corn/soy oil placebo; oil not containing DHA...dosage based on body weight
Drug: docosahexaenoic acid OR corn/soy oil placebo
daily intake of DHA based on body weight or corn/soy oil placebo(oil not containing DHA; 4 year trial
Other Names:
  • DHA; omega-3 fatty acid
  • OR RANDOMIZED TO corn/soy oil placebo

Detailed Description:

Location & Contact Information:

Retina Foundation of the Southwest, 9600 N. Central Expressway, Suite 200, Dallas, TX 75231 Contact: Dr. D. Hoffman (dhoffman@retinafoundation.org) or Dr. D. Birch (dbirch@retinafoundation.org).

  Eligibility

Ages Eligible for Study:   7 Years to 32 Years
Genders Eligible for Study:   Male
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Diagnosis of RP by a retinal specialist
  • Clinical diagnosis consistent with X-linked inheritance
  • Enrolling minors and young adults (early onset of X-linked disease; ages 7 to 32)
  • Measurable cone ERG responses --patients with less than 0.64 microvolt response to 31-Hz flicker will be excluded as they are more likely to become undetectable during the study
  • Both eyes must meet entry criteria as both will be tested (i.e., no cataracts requiring surgery or retinal detachments).
  • Media clarity sufficient for fundus photography
  • Able to return to study site at yearly intervals
  • Willing to supply blood samples at 6-month intervals
  • Judiciously take the placebo or DHA supplement for the 4-year study duration
  • Patient/parent/guardian understands and signs consent form.

Exclusion Criteria:

  • Excessive fish consumption (e.g., cold water fish such as salmon, tuna, sardines) and/or fish oil supplementation (or other oil containing DHA)
  • Baseline RBC-DHA levels showing evidence of supplementation (a typical level of RBC-DHA in normals is about 3.8%)
  • Chronic metabolic disease that may interfere with fatty acid metabolism or require anti-coagulant medication

No ethnic or racial groups will be excluded.

  Contacts and Locations
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, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00100230

Locations
United States, Texas
Retina Foundation of the Southwest
Dallas, Texas, United States, 75231
Sponsors and Collaborators
Retina Foundation of the Southwest
Foundation Fighting Blindness
DSM Nutritional Products, Inc.
Investigators
Principal Investigator: Dennis R. Hoffman, Ph.D. Retina Foundation of the Southwest
  More Information

Additional Information:
No publications provided by Retina Foundation of the Southwest

Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Dennis Hoffman, Senior Research Scientist (Retina Foundation of the Southwest), Retina Foundation of the Southwest
ClinicalTrials.gov Identifier: NCT00100230     History of Changes
Other Study ID Numbers: 2543, FD-R-002543-01
Study First Received: December 27, 2004
Last Updated: October 10, 2013
Health Authority: United States: Food and Drug Administration

Keywords provided by Retina Foundation of the Southwest:
retina
electroretinography
clinical trial
docosahexaenoic acid
omega-3 fatty acid
x-linked inheritance

Additional relevant MeSH terms:
Genetic Diseases, Inborn
Retinitis
Retinitis Pigmentosa
Genetic Diseases, X-Linked
Retinal Diseases
Eye Diseases
Eye Diseases, Hereditary
Retinal Dystrophies
Retinal Degeneration

ClinicalTrials.gov processed this record on September 15, 2014