Dallas, Texas – (August 2010) – The Retina Foundation of the Southwest is teaming up with two other sites in the U.S. to investigate the use of valproic acid, an FDA-approved drug, to treat autosomal dominant retinitis pigmentosa (adRP). This new three-year clinical trial is set to begin this fall.

Valproic acid is a promising new potential treatment for adRP. Previous studies in the laboratory have demonstrated that the drug maintains the thickness of the outer retinal layer, slowing down further loss of vital photoreceptor cells needed for sight. Valproic acid has already been approved by the FDA for treatment of epilepsy. The fact that the drug is already available and proven safe in the treatment of another disorder will give the clinical trial an advantage in investigating the drug for treatment of adRP.

“Developing a new drug from discovery to clinical trials takes an enormous amount of time and money. With valproic acid we have a drug for which the initial safety work has already been done for us. This is a golden opportunity to piggy-back on the work of others and to rapidly move into patient trials,” said Dr. David Birch, Chief Scientific & Executive Officer and Director of the Rose-Silverthorne Retinal Degenerations Lab that will be conducting the study.

Autosomal dominant retinitis pigmentosa is a form of RP that carries a 50% chance of being genetically passed down from one parent who has one defective gene paired with one normal gene even if the other parent is unaffected. This form of RP along with other forms result in gradual loss of vision with varying rates of progression. Many patients with RP become legally blind by the age of 40.

“We plan to conduct the best trial we can possibly conduct because we owe it to the patients to provide a definitive answer to whether this drug is helpful,” said Dr. Birch.

Because RP gradually destroys vision over a number of years, slowing down the loss of photoreceptor cells may preserve sight for many patients affected by this devastating disease.

“Initial reports from uncontrolled clinical experience suggest that valproic acid may actually increase the visual field. However, even a slight slowing of the rate of degeneration could help preserve sight for patients because of the gradual nature of the disease,” said Dr. Birch.

The Retina Foundation is looking forward to studying the effectiveness of this drug as a treatment for patients with adRP. There is currently approval for preliminary studies to see if valproic acid might also be useful for treating other forms of RP and other retinal diseases. Results from these studies may allow for expansion of the adRP trial at a later date to test patients with other forms of RP and retinal disease.

“We have a large population of patients available in Dallas with adRP. We will be contacting those that we feel will qualify for the trial. Ultimately, we hope to expand the trial to include other forms of RP,” said Dr. Birch.

Valproic acid is currently not FDA-approved for treatment of adRP or other forms of degenerative eye diseases. Patients affected with adRP and other retinal diseases should not use valproic acid for treatment of RP at this time. FDA-approval of valproic acid for adRP will depend upon the outcome of the clinical trial.

“We are participating in this trial because we are encouraged by the preliminary findings in the laboratory. We are satisfied that we can conduct the trial at minimal risk to the patient. Time will tell whether valproic acid has a significant benefit to our patients,” said Dr. Birch.

Patient recruitment at the Retina Foundation of the Southwest will be through the Southwest Eye Registry. However, there will be an ongoing effort to keep patients aware of new developments from this trial as we move forward in discovering treatments for eye disease.

According to Dr. William Snyder, Chairman of the Board, “Our participation in this trial reflects our key role in bridging the gap between the laboratory and the clinic. We see clinical trials as an important component of the mission and goals of the Retina Foundation.”

Click here to read about more clinical trials at the Retina Foundation of the Southwest.