Exciting New Treatment for Hereditary Blindness

Last month biotechnology company Spark Therapeutics announced it had received FDA approval for its patented gene therapy Luxturna, intended to treat a rare genetic form of vision loss and blindness.

Luxturna is designed to help people who have rare mutations in a gene called RPE65, which is needed to make a protein found in the retina, that is vital for normal vision. People who inherit two mutated copies of the RPE65 gene experience progressive vision loss starting shortly after birth. Initially, patients may notice a deterioration in their peripheral vision leading to “tunnel vision” and they may also have difficulty seeing in low light. Eventually patients may begin to lose their central vision as well, leading to total blindness.

Spark Therapeutics, the makers of Luxturna, estimates that 1,000 to 3,000 people are affected by RPE65-related eye diseases in the United States alone. At present, there are no drugs available to treat these diseases.

Gene therapy is a rapidly developing area of science which involves the insertion of genes into a patient’s cells and tissues to treat a hereditary disease in which a defective mutant copy of the gene (allele) is replaced with a functional one. In the case of Luxturna, a carrier virus called a vector is used to deliver the therapeutic RPE65 gene to the patient’s retinal cells, restoring sight. The gene therapy is administered by injecting the vector virus directly into the patient’s eye.

During a recent trial of Luxturna for patients with Leber congenital amaurosis (LCA), an inherited eye disease caused by RPE65 gene mutations, 90% of patients who received therapy showed improvement in their ability to navigate a maze in low to moderate lighting conditions. In contrast, none of the participants who didn’t receive treatment with Luxturna (control group) were able to navigate the maze under the lowest lighting conditions.

While these studies only tested treatment with Luxurna in patients with LCA, Spark therapeutics anticipates that the drug may also be suitable for patients with other retinal diseases caused by RPE65 gene mutations, however further trials are required to measure its long-term effectiveness.

The release of Luxturna is the first time a gene therapy for an inherited disease has been approved in the United States, however it is not yet known when the treatment will be approved for use in Australia

Original source article published on Live Science.