Novel treatment related to age-related macular degeneration shows encouraging results

Tampa, FL-Results from an interim analysis of an ongoing phase II study show fenretinide (Sirion Therapeutics) is well-tolerated and exhibits promising biological activity in slowing lesion growth in patients with advanced geographic atrophy (GA) associated with age-related macular degeneration (AMD), according to Roger Vogel, MD.

Administered orally, fenretinide leads to a dose-dependent, reversible reduction in circulating levels of retinol by competing with the vitamin A compound for binding to its carrier protein, retinol binding protein (RBP). The premise for investigating fenretinide as a treatment for slowing progression of GA is based on the hypothesis that it would reduce retinol delivery to the eye and thereby decrease the accumulation of vitamin A metabolites (A2E) that are toxic to retinal pigment epithelial cells and photoreceptors.

"Results from our interim analysis of data collected at 12 months in the phase II study and in a smaller group of patients who reached the 18-month visit show that fenretinide treatment is associated with a dose-related reduction in serum RBP and a dose-related reduction in GA lesion growth," said Dr. Vogel, senior vice president and chief medical officer, Sirion Therapeutics, Tampa, FL. "These data support our hypothesis. However, confirmation is pending completion of the 24-month study."

"Prior to its investigation as a treatment for geographic atrophy, fenretinide had already been studied by Johnson & Johnson as a cancer-preventive agent," Dr. Vogel said. "While it failed to show any efficacy for that indication, 8,000 patient years of safety data provided evidence that fenretinide was well-tolerated at doses equivalent to those being tested in the GA trial. Based on that background, Sirion Therapeutics was able to begin its clinical trial program with a phase II study."