Luxturna, the first gene therapy that targets a disease caused by mutations on a specific gene, was approved today by the FDA for the treatment of patients with biallelic RPE65 mutation-associated retinal dystrophy.
Luxturna uses a modified adeno-associated virus, which infects humans but does not cause a disease, to deliver a healthy version of the RPE65 to the retina. In clinical trials, patients who received Luxturna maintained functional vision at a better rate than patients in the control group.
Mutated genes can cause the generation of defective or inactive proteins, often manifesting in the form of chronic diseases or conditions that diminish the patient’s quality of life. RPE65, a key enzyme expressed in the retinal pigment epithelium (RPE), is essential for the regeneration of pigments for rod and cone-mediated vision. Mutations of the enzyme are associated with impaired vision, which often progresses to complete blindness. Biallelic RPE65 mutation-associated retinal dystrophy affects between 1,000 and 2,000 individuals in the US and is often diagnosed during childhood or adolescence.
Gene therapy uses a vector to deliver the engineered gene into the cell, to modify cells inside the body in order to treat or prevent a disease. The vector can be administered intravenously in the affected area where, if successful, it will penetrate cells and produce the desired protein. Another strategy is to take a sample of the patient’s cells, expose them to the vector and then return them to the patient.
While Luxturna can only be used by a comparatively small number of patients, this treatment showcases the potential of gene therapy for the generation of medicines can target specific genes. “I believe gene therapy will become a mainstay in treating, and maybe curing, many of our most devastating and intractable illnesses,” said FDA Commissioner Scott Gottlieb.