Ron Philip, Chief Commercial Officer of Spark Therapeutics, discusses biallelic RPE65 mutation-associated retinal dystrophy, a rare retinal disorder.

The RPE65 gene provides instructions for making a protein that is essential for normal vision. The RPE65 protein is produced in a thin layer of cells at the back of the eye called the retinal pigment epithelium (RPE). This cell layer supports and nourishes the retina, which is the light-sensitive tissue that lines the back of the eye.

The RPE65 protein is involved in a multi-step process called the visual cycle, which converts light entering the eye into electrical signals that are transmitted to the brain. When light hits photosensitive pigments in the retina, it changes a molecule called 11-cis retinal (a form of vitamin A) to another molecule called all-trans retinal. This conversion triggers a series of chemical reactions that create electrical signals. The RPE65 protein then helps convert all-trans retinal back to 11-cis retinal so the visual cycle can begin again.

Spark Therapeutics’ Luxturna (voretigene neparvovec-rzyl) is an adeno-associated virus vector-based gene therapy indicated for the treatment of patients with confirmed biallelic RPE65 mutation-associated retinal dystrophy.