Seventeen-year-old Christian Guardino is something of a rock star these days, and not only because he crushed it on America’s Got Talent last summer. He is also one of the first people to be treated successfully with a new gene therapy for a rare form of blindness.
The therapy is called Luxturna, and after many years of research, it looks like it’s about to be approved by the FDA. An FDA advisory committee recently recommended approval of the new drug with a unanimous vote of 16 - 0, indicating that all committee members supported the application without any significant concerns. The final decision won’t come until January, but the agency generally follows the advice of these special advisory committees.
If Luxturna is approved, it will be the first gene therapy on the market in North America for an inherited disease. It was developed to treat a form of progressive blindness called Leber congenital amaurosis (LCA), which is caused by a defective gene called RPE65. LCA is recessive, which means that both parents have to be carriers in order for a child to develop the disease. If there is no good copy of this gene to produce the right proteins, the retinas of the eyes stop working as they should, and patients generally lose their sight by the time they hit their teens.
Christian Guardino was diagnosed with this disorder when he was just a few months old. His mother, Elizabeth Guardino, noticed Christian wasn’t tracking moving objects the way most babies do.
“He wouldn’t make any kind of visual connection with us or respond to facial expressions,” she told The Daily Beast. “He only wanted to stare at the light—he would crane his neck into contortions until he could see a light bulb or the sun.” He also developed a jerking motion of his eyes, called nystagmus, common to most LCA patients.
A pediatric eye specialist ran an ERG (electroretinogram), which measures the response of the eyes and the brain to flashes of light. The procedure was tough for his parents to watch. “They had to put these lenses into his eyes, with wires attached to them,” Elizabeth said.
Unfortunately, the family was originally misinformed about the impact the LCA would have on Christian’s vision as he grew older. “We were told that he’d always have some trouble, but that he would stay stable or even improve,” she says. “We didn’t learn that he was actually going to go completely blind until he was about 11 years old.”
Shocked by that news, Christian’s mother sought more information online. She stumbled on a Facebook support group for LCA patients and their families. There, she learned about special conferences hosted by the Foundation Fighting Blindness, where families could meet with specialists and researchers. At the first conference they attended, Christian’s family met the doctors who were conducting a clinical trial of the new RPE65 gene therapy. Although there are 18 different genes that can cause LCA, RPE65 just happened to be what Christian had.
So, just 13-years-old, Christian was treated with the experimental therapy.
Luxturna is being developed by a company called Spark Therapeutics, which was founded by researchers at the Children’s Hospital of Philadelphia. In order to get the gene to stay in the eyes and produce the normal RPE65 protein, Spark researchers began in the lab by inserting DNA that contained the gene for RPE65 into a circular virus called AAV, which is harmless to humans. During treatment, a fluid containing millions of copies of this gene/virus hybrid is injected directly into the retina, where they enter the cells. The viral particles essentially “infect” the cells of the eye and start producing healthy molecules of RPE65, which then help the retina work properly.
According to a recent review article in the journal Genes, there are a number of reasons why a treatment for eye disease was one of the first gene therapies to be recommended for approval. The eye and retina are easily accessible, and are easy to monitor. In clinical trials, one eye can serve as an untreated control. The eye also has a relatively small volume, and it’s relatively protected from the immune system, so there is less risk of unwanted effects caused by introducing foreign molecules into the body.
The final step before approval by the FDA was a Phase 3 clinical trial. Ninety-three percent of the patients who received the Luxturna gene therapy in that trial were able to navigate through a maze in low light significantly better than they could before the treatment. Some of those patients—including Christian—experienced up to an 80 percent improvement in visual function, giving them nearly normal vision. Side effects have been minimal, and it looks like the visual improvements can last for at least several years.
There are some caveats to consider, however. Luxturna is not a total cure for the blindness caused by LCA, especially in older patients. According to a presentation at the 2017 Annual Meeting of the American Academy of Ophthalmology, the treatment may only allow patients to see shapes and light, so that they can get around without a cane or a guide dog. In addition, according to the FDA advisory committee, individuals with more advanced disease did not appear to benefit from the treatment (PDF).
Another consideration is the astronomical cost of the new therapy. According to analysts at RBC, the predicted cost for one course of treatment with Luxturna may be almost $1 million per patient (PDF). Can such a high cost be justified?
Part of the reason for the expense is to compensate for the number of years of development, and the high cost of clinical trials. There are also many other diseases whose costs add up over the lifetime of a patient, but these costs are less obvious because they’re paid monthly. For example, the lifetime costs for a patient with sickle-cell disease may add up to as much as $460,000. And annual costs for a patient with hemophilia can reach $140,000 per year, reaching the $1 million mark in just seven years.
A number of commentators think new pricing models need to be introduced for therapies that require only a single treatment—or at most once every few years. They suggest that, rather than the standard model that calculates reimbursement at monthly or annual rates, this new model should be based on the benefit to each patient over their lifetime.
In an article in the journal Health Affairs, several experts discuss the problem and suggest that “value-based payment arrangements” for gene therapies are one solution. This might involve a “pay-for-performance” pricing model, which would spread the cost of the therapy over time by charging users or their insurance company a smaller, annual fee for as long as therapy remains effective.
Steve Miller, chief medical officer of pharmacy-benefit services company Express Scripts notes in a blog post: “These therapies are administered once, unlike nearly all other medications that are repeatedly taken over time. And therein lies the challenge. Pharmaceutical companies have a single opportunity per patient to get paid… The health care system isn’t set up for this type of economic model. Ideas on the table include paying for a treatment over time, establishing insurer risk pools and financing one-time payments.”
In Christian Guardino’s opinion, cost shouldn’t even enter into the equation. “There are people who have the disease that I have,” he told The Daily Beast, “and they don’t have much money, and they just need this treatment. Because it’s the only thing that can help them. It has changed my life.”
Elizabeth Guardino concurs. “I didn’t really understand what it was like for Christian,” she says. “But once he could see better, he was able to explain it to me. Before he had the gene therapy, a normal, sunny day for us was like wearing sunglasses at dusk on a rainy day for him. And if that’s not a reason for this [treatment] to become available for others, I don’t know what is. Because they’re living in a dark, dangerous world.”
Before Christian was treated with the new gene therapy, he couldn’t recognize people’s faces, and he couldn’t see the full moon crossing the night sky. Now, he says, “I can see the stars.”