Spark Therapeutics has priced its recently approved gene therapy Luxturna to treat a rare form of inherited blindness at $850,000, with a payment structure that could set a precedent for other gene therapies. Spark won a historical first in December when the US Food and Drug Administration approved Luxturna (voretigene neparvovec) to treat children and adults with a retinal dystrophy, caused by a mutation in both copies of the RPE65 gene, which progresses to complete blindness (Nat. Biotechnol. 36, 6, 2018). Although Luxturna is priced lower than the $1 million estimated by Wall Street analysts, at $425,000 per eye, Spark came under fire from patient advocates. The president and founder of Patients for Affordable Drugs, David Mitchell, said in a statement: “the new payment models are merely a way to disguise a price that is simply too high.” To ease the payor pressure, the Philadelphia-based Spark has come up with an outcome-based reimbursement, and is working on an agreement with the Centers for Medicare and Medicaid Services to collect payments over several years. Under the plans, the company will charge insurers for its one-time gene therapy treatment if patients' vision scores in full-field light sensitivity threshold tests improve at 30 and 90 days and at 30 months. The therapy is a modified adeno-associated virus that delivers normal copies of human RPE65, which is essential for normal vision, to the retinal cells through a subretinal injection. Luxturna must be given only to patients who have viable retinal cells. In the data supporting the treatment's approval, patients' ability to complete an obstacle course at low light levels improved, compared with a control group. An independent US non-profit organization that evaluates clinical and cost effectiveness of new medicines said on January 12 that despite the money-back strategies proposed by the company, Luxturna's price tag is far too high. The Institute for Clinical and Economic Review stated that only with a significant price discount would Luxturna meet cost-effectiveness standards.