The FDA Offers Up Children to a Log, Brutal, and Fatal End
By Matthew Ellinwood
The effects of Sanfilippo syndrome in small children are so devastating that the rare disease is often known as "childhood dementia."
About one in 70,000 newborns inherit this disorder. The affected children look normal at birth, but between ages one and six they begin to develop a host of symptoms, including severe developmental delays, seizure-like episodes, and losses in cognition, vision, and hearing. Without exception, Sanfilippo leads to an early death.
I have devoted my career to understanding this cruel disease and to looking for ways to treat or cure it. Thankfully, therapies for Sanfilippo are on the horizon -- for the first time.
Yet there the Food and Drug Administration is holding potential Sanfilippo therapies to an impossible and inhumane standard.
Sanfilippo syndrome results from a deficiency of one of four enzymes needed to break down long chains of carbohydrate molecules. These undegraded molecules accumulate with devastating effects within a child's brain, leading to a heartbreaking neurodegeneration.
The problem lies in the standard approach the FDA is applying in evaluating Sanfilippo syndrome therapies. Under the agency's traditional approval path, a drug must undergo randomized trials that demonstrate clinical benefits.
This process makes sense for common diseases, such as diabetes, with reversible symptoms that can be observed within weeks.
But that's not the case with Sanfilippo syndrome.
Under the agency's "accelerated approval" path, the FDA can make a treatment available on the basis of a "surrogate endpoint" -- a measurable biochemical change that predicts forthcoming improvements.
Sanfilippo syndrome is exactly the kind of illness regulators had in mind when they created accelerated approval. The straightforward biology behind Sanfillipo syndrome should make approving treatments easy. Yet the FDA has refused to allow Sanfilippo treatments access to the accelerated approval path, insisting instead on traditional approval.
That's a disaster for current and future patients.
Because Sanfilippo syndrome is so rare, recruiting enough patients for traditional clinical trials is a challenge. This obstacle has already forced several research programs to close down. In fact, a biotech executive just shut down his world-leading clinical trial on Sanfilippo, citing the FDA's regulatory process as a key obstacle.
Then there's the gut-wrenching ethics issue. The FDA's requirements demand control groups that receive either delayed treatment or no treatment for a year or more. A Sanfilippo patient in one of these groups could hit the point of no return in their illness -- beyond which future treatments would be ineffective. In other words, participation in these trials could be a death sentence.
Research suggests that effective Sanfillipo treatments will need to begin before age 2. Forcing a 1-year-old child with the disease to remain in a placebo group for a year could permanently eliminate the possibility of improvement. Is this the only way to evaluate promising treatments? Do some children have to die in order to satiate our desire for data?
Effective treatments for Sanfilippo are finally within reach. The only question is whether the FDA will allow modern medicine to deliver on this promise.
Matthew Ellinwood, D.V.M., Ph.D. is the chief scientific officer of the National MPS Society. This piece originally ran in Salon.
