A novel pharmacologic approach (AL-8309, Alcon Laboratories) protects the retina and the retinal pigment epithelium (RPE) from severe oxidative stress, according to researchers. The small-molecule, retinal cytoprotectant drug was tested in a photo-oxidative rat model in which animals were exposed to blue light for several hours.

The result was permanent damage to the a-wave amplitude. AL-8309A tested in rats provided complete protection of the a- and b-wave amplitudes, according to Carl Romano, PhD, senior director, retinal research, Alcon Laboratories.

“The drug preserves the cellular elements with pretreatment,” he said.

AL-8309B, a topical drug, given one to two times daily provided significant protection of the a- and b-wave amplitudes.

“AL-8309 decreases CEP-adduct formation and boosts the antioxidative capability of the retina,” he said. “No complement deposition was detected in the retina with treatment. The ability of the retina to deal with blue light appears to be enhanced by the drug.”

The phase II/III geographic atrophy treatment evaluation currently is recruiting patients. The 2-year study will include a placebo group and two active treatment groups that receive two doses of AL-8309B, 1.75% and 1%, for treating geographic atrophy. The primary end point is the rate of progression of geographic atrophy measured by fundus autofluorescence.

“AL-8309 protects the photoreceptors and RPE cells from photo-oxidative stress and may be a useful pharmacotherapy for AMD,” Dr. Romano concluded.