Nolan and Jack Willis, twins from upstate New York, and just 10 other boys took part in a clinical trial that led to the approval last fall of the very first drug to treat their rare, deadly muscle disease.
Now the Willis boys are again test cases as a different type of medical question comes to the fore: whether insurers will cover the controversial drug, Exondys 51, which can cost more than $1 million a year even though it’s still unclear if it works.
The boys’ insurer, Excellus BlueCross BlueShield, refused to cover the cost of the drug because the twins, who are 15, can no longer walk. Their disease, Duchenne muscular dystrophy, overwhelmingly affects boys and causes muscles to deteriorate, killing many of them by the end of their 20s.
“I’m cycling between rage and just sadness,” their mother, Alison Willis Hoke, said recently, on the day she learned that an appeal for coverage had been denied. For now, the company that sells the drug, Sarepta Therapeutics, is covering the treatment’s costs, but Mrs. Hoke does not know how long that will last.
The desperation in Mrs. Hoke’s voice reflects a sobering reality for families of boys with the disease since their elation last fall over the drug’s approval. Because the Food and Drug Administration overruled its own experts — who weren’t convinced the Exondys 51 had shown sufficiently good results — and gave the drug conditional approval, many insurers are now declining to cover it or are imposing severe restrictions that render patients ineligible.
The story of Exondys 51 raises complex and emotionally charged questions about what happens when the F.D.A. approves an expensive drug based on a lower bar of proof. In practice, health insurers have taken over as gatekeeper in determining who will get the drug.
Disputes like the one over the Duchenne drug are likely to become more commonplace in the coming months. A federal law, passed last year, directs the agency to remove barriers to approving drugs and medical devices, and its new commissioner, Dr. Scott Gottlieb, has called on the F.D.A. to be more lenient, especially when it comes to rare pediatric diseases.
While insurers once covered drugs for rare diseases as a matter of course, that may be changing now that a wave of expensive drugs have reached the market. The pharmaceutical industry has been in hot pursuit of an increasingly enticing demographic target: An estimated 30 million people in the United States — about 10 percent of the population — are living with one of roughly 7,000 rare diseases.
The agency’s approval of Exondys 51, though, prompted a rebellion among some insurers, who are refusing to play along and saying they are concerned about the cumulative impact of such breathtakingly expensive drugs on health care costs. Anthem, one of the nation’s largest insurers, calls Exondys 51 “investigational” because the F.D.A. reserved the right to withdraw it from the market if future clinical trials fail to show it works.
Another insurer, Premera Blue Cross, went so far as to tie coverage to an invasive procedure — a muscle biopsy — but then rescinded the requirement.
“I’m reading a lot of denial letters,” said Christine McSherry, who until recently served as executive director of the Jett Foundation, an advocacy group that guides families through the insurance appeal process. Her insurer, Blue Cross Blue Shield of Massachusetts, is covering the drug for her son, Jett, through next April. “It’s very disheartening to have worked that hard, and to have sacrificed that much, and to now have to battle the insurance companies.”
The drug’s high cost is driving the resistance. While the drug manufacturer, Sarepta, has said Exondys 51 costs about $300,000 a year per child, the price, based on a child’s weight, can be much higher. For the dozen boys in the main clinical trial, the average list price would be more than double Sarepta’s quote — $750,000 each, according to an analysis by the drug benefit firm Prime Therapeutics.
“I think a lot of the advocates in this space maybe thought that getting a drug on the market was the goal of their advocacy,” said Dr. Aaron S. Kesselheim, an associate professor of medicine at Harvard University who voted against the drug’s approval as part of an F.D.A. advisory committee. “The goal of the advocacy should have been getting a product on the market, and making sure that it’s available at a reasonable cost.”