Debate over Duchenne drug hits fever pitch as D-day approaches


The deadline for a final marketing decision at the FDA on Sarepta’s Duchenne muscular dystrophy drug eteplirsen arrives on Thursday. And the lead up to D-day continues to see patient advocates and their supporters passionately squaring off against some prominent experts who believe that an approval based on data regulatory insiders have deemed woefully inadequate would create a dangerous precedent at the FDA.

Quite a few analysts give Sarepta only a 15% to 20% chance of success in gaining an accelerated approval this week, and that figure would likely be much lower if not for the powerful lobbying campaign that has enlisted the support of some prominent newspapers and politicians.

“Patients are crying out for the FDA to hear them: they are engaged and knowledgeable and only want the agency to do what is already in their power,” wrote senators Dan Coats and Ron Johnson in a letter to the FDA a few days ago, part of a stream of appeals from elected officials in recent months.

But if eteplirsen is approved based on lobbying after a negative expert panel vote and a clear rejection of Sarepta’s case by regulators in their internal review--which dismissed Sarepta’s attempts to offer evidence of efficacy based on a tiny, deeply flawed 12-patient study--the agency will face a backlash from an industry that has been lectured over and over again about the need to produce solid, credible data on efficacy and safety for any marketing application.

“If this drug is approved--on the skimpiest, most pathetic data I’ve ever seen--then it is going to set a precedent that is very uncomfortable,” Diana Zuckerman, president of the National Center for Health Research, told the Financial Times.

Heightening the drama this week, the only two potential near-term rivals in this field were dismissed out of hand by the FDA earlier this year. If eteplirsen is rejected, patients will have nothing on the market for this disease, a point advocates hit on repeatedly.

Noted bioethicist Art Caplan at New York University Langone Medical Center tackled the FDA’s dilemma recently in a commentary that reinforced the argument that no biotech should be allowed to rely on a lobbying campaign to force an approval in the absence of supporting data. 

“The FDA's job is to get drugs out on the market that are proven safe and effective,” he noted. “In this case, there simply were not enough data in place from the corporate sponsor to make that possible. At the same time, companies shouldn't be deluding patients and families into thinking that they have enough data to go to the FDA. They shouldn't approach the FDA unless they truly have the available data to get approved. Relying on patient testimonials and lobbying is not the path to drug approval.

“The FDA must take the long view by not approving treatments unless the evidence is truly there and supported by a sound study design in order to convince experts.”

The FDA does have one other option. There’s been growing speculation in recent days that the FDA may just punt, offering a regulatory delay in its final decision to assist Sarepta as it recruits patients for its ongoing study of eteplirsen. 

There’s only one thing that’s absolutely certain at this point: Whichever way the FDA turns, there will be a storm of protest.

There’s no way to avoid a controversy now.