Recently the FDA approved Luxturna (voretigene neparvovec), a drug from Spark Therapeutics, which treats some eye diseases caused by a defective gene. The abnormal RPE65 gene in the eye causes a group of conditions called retinal dystrophies, which include retinitis pigmentosa (RP) and Leber congenital amaurosis. Patients with these diseases progressively lose vision then go blind. In the United States there are 1,000-2,000 people affected.
Luxturna is essentially the healthy RPE65 gene. Luxturna is injected into the eye, where the healthy gene starts working in place of the disabled defective gene. In clinical trials, many patients with these diseases who received a single eye injection of Luxturna had significant improvement in their ability to see light and move around. This improvement lasted for two years and may last beyond three years.
Luxturna is notable for several reasons. It is the first gene therapy to treat an inherited disease to be approved in the United States. It is also the first treatment to improve vision in retinal dystrophies. But what has garnered the most attention is its price $850,000 to treat both eyes. Amazingly, this price tag is cheaper than many expected.
Developing any drug is expensive these days. Beyond that, this high price results from the small number of patients to treat and the fact that it is a one-time treatment, which provides little opportunity for Spark Therapeutics to make money. Other drugs for rare diseases have similarly high costs. For example Spinraza, a treatment for spinal muscular dystrophy, costs $750,000 for the first year and then $375,000 for each year after.
Is Luxturna worth the cost? For those who see and live better from treatment with Luxturna, presumably the answer is yes. For everyone else, this may be a difficult question to answer. How much is your sight worth to you? What would you pay to see? See just a little bit? Difficult questions, yes, but ones that we may have to ask ourselves as medical costs continue to increase and newer expensive drugs are developed.