The FDA has approved a landmark gene therapy for vision loss—the first ever to fix a faulty gene within a patient’s body—but the therapy’s owner isn’t yet saying how much the drug will cost.
The approval goes to Philadelphia-based Spark Therapeutics (NASDAQ: ONCE) for voretigene neparvovec (Luxturna) to treat patients who have inherited a mutation on the RPE65 gene. This faulty gene leads to eye disorders that gradually rob children and adolescents of their vision. Some patients end up completely blind. Between 1,000 and 2,000 patients in the U.S. have RPE65 mutations, according to the FDA.
The therapy uses an engineered virus to deliver a correct version of the RPE65 gene directly into the eye’s retinal cells.
In its announcement, the FDA also signaled that it is preparing to evaluate an increasing flow of new gene therapies. It will release new guidance for gene therapy developers next year. Gene therapies for blood diseases like hemophilia, sickle cell disease and beta-thalassemia, neurological disorders such as Parkinson’s disease, and more rare conditions like Duchenne muscular dystrophy, are all being tested in human clinical trials.
“I believe gene therapy will become a mainstay in treating, and maybe curing, many of our most devastating and intractable illnesses,” FDA Commissioner Scott Gottlieb said in a statement. “We’re at a turning point when it comes to this novel form of therapy and at the FDA, we’re focused on establishing the right policy framework to capitalize on this scientific opening.”
Perhaps an even bigger question for drug companies: Will insurers pay for sky-high prices? To be worthwhile, a gene therapy should offer a long-lasting treatment for a disease, perhaps even a cure. But there is no evidence yet showing such therapies will prove durable. Drug makers are still grappling with the potential price of a one-time treatment. UniQure (NASDAQ: QURE) priced its gene therapy alipogene tiparovec, a treatment for a rare metabolic disorder, at $1 million following its 2012 approval in Europe. Earlier this year, uniQure withdrew the therapy, a commercial failure, from the market. A second high-priced gene therapy, GlaxoSmithKline’s Strimvelis, sold in Europe for a rare immune disorder, has also struggled commercially.
A spokeswoman said Spark will announce pricing for voretigene neparvovec in January. On Spark’s most recent earnings call, CEO Jeff Marrazzo suggested that voretigene neparvovec could have a price eclipsing $1 million based on its impact on a patient’s quality of life, medical costs, and other indirect costs “such as unemployment and lost caregiver wages.” Whatever price it sets, Spark will argue that the therapy has begun to show durability. The company has data showing that its effects last four or more years.
In previous interviews with Xconomy, Marrazzo has expressed concern that the market is not providing drug makers the right incentives to develop one-time treatments. In some instances, insurers limit their coverage of therapies due to the small number of patients studied in clinical trials. (Spark’s approval was based on results from 41 patients.) But Marrazzo has said Spark can counter with data showing that 93 percent of patients in Spark’s Phase 3 study regained some amount of visual function.
In October, an FDA advisory panel unanimously recommended approval of voretigene neparvovec. The FDA took that recommendation to heart. The 41 patients in Spark’s studies were between the ages of 4 and 44 and had the mutation to the RPE65 gene. In a 31-patient Phase 3 study, patients who received the Spark treatment were evaluated on their ability to navigate an obstacle course in varying light levels. Patients treated with voretigene neparvovec showed significant improvement navigating the course compared to a control group. The most common side effects from the therapy were eye redness, cataract, increased intraocular pressure, and retinal tear.
Spark expects voretigene neparvovec will become available in “select treatment centers” by the end of the first quarter, the spokeswoman said.