FDA panel votes against Sarepta’s drug for Duchenne muscular dystrophy

A federal advisory panel voted Monday that a drug from Sarepta Therapeutics was not effective for treating Duchenne muscular dystrophy, a rare and fatal muscle-wasting disease. About 13,000 children, mostly boys, are afflicted.

The vote came after a daylong session punctuated by emotional pleas from dozens of parents and their children, some of whom appeared in wheelchairs, to describe how the Sarepta drug, called eteplirsen, made a substantial difference in clinical trials. Their testimony was balanced by presentations from US Food and Drug Administration staff who took a dim view of the Sarepta trial data.

The panel vote, however, is not the last word. The agency must now determine by May 26 whether to follow the recommendation.

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One FDA official appeared to leave the door open as the meeting concluded. “I assure you, we listened very carefully and will take the information we heard here today under serious consideration,” Dr. Billy Dunn, who heads the FDA division of neurology products, told the crowd.

Beyond this one medicine, the meeting was something of a caucus on regulatory policy.

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The fate of the Sarepta drug has been closely watched as a litmus test for an intensifying struggle between the FDA and patient groups that want the agency to take a more expansive view toward approving medicines for unmet medical needs. In this instance, patient advocates hope the FDA will use the accelerated approval process to endorse eteplirsen. This approach relies on a substitute outcome in a clinical trial to suggest a drug may have, but not does not guarantee, a benefit.

Acknowledging the climate, Janet Woodcock, who heads the agency division that approves drugs, attempted to appease the large crowd of DMD parents and their supporters.

“It’s possible to reach different conclusions based on the data presented today,” she said during brief remarks shortly after the meeting began. “Failing to approve a drug that actually works in devastating diseases — these consequences are extreme.”

In recent months, the FDA had rejected two other drugs for DMD. And during the run-up to Monday’s meeting, FDA staffers released lengthy documentation that took a dim view of the Sarepta drug.

The possibility that DMD parents faced a “three strikes” scenario lent an unprecedented sense of urgency to the proceedings.

The session, in fact, was easily one of the most politically charged FDA advisory panel meetings held for a new drug approval.

The first public speaker underscored the tension. Representative Mike Fitzpatrick, a Republican from Pennsylvania, noted that more than 100 lawmakers had signed a letter that urged the agency to endorse the Sarepta treatment. All but one of the 52 slotted public commentators spoke in favor of approval.

Among them was one boy with DMD, Billy Ellsworth, who appeared with his mother and testified before the crowd. “I’m going to beat this bloody disease but I need your help,” he told the panel, prompting cheers and applause from the overflow audience. “FDA, please don’t let me die early.”

Much of the day, however, focused on the technical aspects of whether the clinical trials that tested eteplirsen demonstrate whether the drug is actually beneficial.

At issue was whether eteplirsen can sufficiently produce higher levels of a protein called dystrophin. Without this protein, muscle fibers degenerate and voluntary movement becomes impossible. The FDA staff had raised doubts about the veracity of a small, 12-patient clinical trial that Sarepta relied on to make its case, as well as the viability of six-minute walking tests that trial participants underwent.

The agency usually views small trials with skepticism. And during the meeting, FDA officials reiterated such concerns.

One FDA official, Dr. Eric Bastings, told the panel that there was “no apparent correlation between muscle levels of the protein dystrophin and a change” in the boys’ performance in a walk test.

The panel took a mixed view. In a 7-to-6 vote, they decided the drug failed to demonstrate that it produced enough dystrophin to yield a clinical benefit. This is the basis for using the accelerated approval process.

Seven panelists also voted the drug was not effective in treating DMD. Three voted the drug was effective, while three others abstained. “The data wasn’t there to approve on basis of one poorly controlled trial,” Dr. Caleb Alexander, a physician-scientist at the Johns Hopkins Bloomberg School of Public Health and the panel chair, said in summarizing the vote.

Nonetheless, the FDA is under pressure to demonstrate flexibility in listening to patients as part of the drug review process — a mandate that was written into a 2012 law.

One Wall Street analyst believes no one should be surprised if the FDA does approve the drug.

“Everyone was visibly moved by the audience and their testimony, and that is not going to go unnoticed,” said Steven Brozak, who runs WBB Securities and tracks biotech stocks. “It’s not just political pressure. It’s advocacy pressure of the sort that I’ve not seen since the days of HIV and AIDS. And that can make the difference here.”

The only outright opposition to approval came from Laura Gottschalk, a senior fellow at the National Center for Health Research, a nonprofit think tank. “Unfortunately, the data do not meet a scientific standard of evidence of effectiveness,” she told the panel. “These boys and their families deserve better.”