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, Foundation Fighting Blindness, DSM Nutritionals
Phase:
Phase 2
Details
Lead Sponsor:
Retina Foundation of the Southwest
Collaborators:
DSM Nutritional Products, Inc. Foundation Fighting Blindness