In vitro results showed a significant decrease in the formation of toxic vitamin A aggregates by 7-fold (top right figure).
Animal receiving ALK-001 showed 70% reduction in the accumulation of toxic deposits called lipofuscin (bottom right fig.) and in 80% reduction of vitamin A aggregates (bottom center fig.) in their eyes. This trend continued after 6 and 12 months of treatment.
To measure visual function, electroretinogram (ERG) is used, measuring electrical response of the retina to light signals: after 12 months of treatment, untreated mice showed gradual losses of visual function. The ERGs of mice receiving ALK-001 showed levels similar to normal mice (without the genetic defect) (bottom left figure).
During these experiments on mice, no side effects were noted and the animals were administered the drug for a period of up to 12 months.
The results of these experiments show that preventing the aggregation of vitamin A in the retina could result in preserved visual function in mice with Stargardt disease.
Human clinical studies are the next step. These multi-year controlled studies will be used to assess whether ALK-001 can have a benefit on patients with Stargardt disease.