Amid controversial Sarepta approval decision, FDA head calls for key study retraction

The head of the U.S. Food and Drug Administration (FDA) has called for the retraction of a study about a drug that the agency itself approved earlier this week, despite senior staff opposing the approval.

On September 19, the FDA okayed eteplirsen to treat Duchenne muscular dystrophy (DMD), a rare genetic disorder that results in muscle degeneration and premature death. Several of its top officials disagreed with the drug’s approval, questioning how beneficial it will be for patients, as Forbes, MedPage Today and others reported.

In a lengthy report Commissioner Robert Califf sent to senior FDA officials on September 16 — that was made public on September 19 — he called for the retraction of a 2013 study published in Annals of Neurology funded by the seller of eteplirsen, which showed beneficial effects of the drug in DMD patients. Califf writes in the report:

The publication, now known to be misleading, should probably be retracted by its authors.

In a footnote in the report, Califf adds:

In view of the scientific deficiencies identified in this analysis, I believe it would be appropriate to initiate a dialogue that would lead to a formal correction or retraction (as appropriate) of the published report.

The study was not the key factor in the agency’s decision to approve the drug, according to Steve Usdin, Washington editor of the publication BioCentury; still, Usdin told Retraction Watch he is “really surprised” at the call for retraction from top FDA staff, the first he has come across in the last two decades. 

The 2013 paper was funded by the firm Sarepta Therapeutics, sellers of eteplirsen, which has seen a surge in its shares after the approval. Eteplirsen will cost patients around $300,000 a year. 

DMD affects around 1 in 3,600 boys due to a mutation in the gene that codes for the protein dystrophin, which is important for structural stability of muscles. Eteplirsen is the first drug to treat DMD, and was initially given a green light by Janet Woodcock, director of Center for Drug Evaluation and Research, after a split vote from the FDA’s advisory committee. Despite Califf’s issues with the literature supporting the drug’s use in DMD, he did not overturn Woodcock’s decision, and the agency approved the drug this week.

In 2014, an inspection team visited the Nationwide Children’s Hospital in Columbus, Ohio, where the research was conducted, according to the report. In the report, Ellis Unger, director of the Office of Drug Evaluation I in FDA’s Center for Drug Evaluation, notes:

We found the analytical procedures to be typical of an academic research center, seemingly appropriate for what was simply an exploratory phase 1/2 study, but not suitable for an adequate and well controlled study aimed to serve as the basis for a regulatory action. The procedures and controls that one would expect to see in support of a phase 3 registrational trial were not in evidence.

Specifically, Unger describes concerns about blinding during the experiments, and notes:

The immunohistochemistry images were only faintly stained, and had been read by a single technician using an older liquid crystal display (LCD) computer monitor in a windowed room where lighting was not controlled. (The technician had to suspend reading around mid-day, when brighter light began to fill the room and reading became impossible.)

Unger adds:

Having uncovered numerous technical and operational shortcomings in Columbus, our team worked collaboratively with the applicant to develop improved methods for a reassessment of the stored images…This re-analysis, along with the study published in 2013, provides an instructive example of an investigation with extraordinary results that could not be verified.

Luciana Borio, acting chief scientist at the FDA, is cited in the report saying:

I would be remiss if I did not note that the sponsor has exhibited serious irresponsibility by playing a role in publishing and promoting selective data during the development of this product. Not only was there a misleading published article with respect to the results of Study–which has never been retracted—but Sarepta also issued a press release relying on the misleading article and its findings…As determined by the review team, and as acknowledged by Dr. Woodcock, the article’s scientific findings—with respect to the demonstrated effect of eteplirsen on both surrogate and clinical endpoints—do not withstand proper and objective analyses of the data. Sarepta’s misleading communications led to unrealistic expectations and hope for DMD patients and their families. 

Here’s how Sarepta describes the study’s findings in the press release Borio refers to:

Published study results showed that once-weekly treatment with eteplirsen resulted in a statistically significant increase from baseline in novel dystrophin, the protein that is lacking in patients with DMD. In addition, eteplirsen-treated patients evaluable on the 6-minute walk test (6MWT) demonstrated stabilization in walking ability compared to a placebo/delayed-treatment cohort. Eteplirsen was well tolerated in the study with no clinically significant treatment-related adverse events. These data will form the basis of a New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA) for eteplirsen planned for the first half of 2014.

However, Usdin noted that the drug’s approval and the study are two independent events, adding that the 2013 study just “got the ball rolling” for eteplirsen, and the FDA conducted many of its own experiments analyses, as detailed in the newly released report.

Jerry Mendell, the corresponding author of the study (which has so far been cited 118 times, according to Thomson Reuters Web of Science) from Ohio State University in Columbus, told us the allegations were “unfounded” and said the data are “valid.” Therefore, he added, he will not be approaching the journal for a retraction, noting that the FDA asked him hundreds of questions about the paper and audited the trials.

Clifford Saper, the editor-in-chief of Annals of Neurology from the Beth Israel Deaconess Medical Center (which is part of Harvard Medical School), said in an email:

It takes more than a call by a politician for retraction of a paper. It takes actual evidence.

He added:

If the FDA commissioner has, or knows of someone who has, evidence for an error in a paper published in Annals of Neurology, I encourage him to send that evidence to me and a copy to the authors of the article, for their reply. At that point we will engage in a scientific review of the evidence and make appropriate responses.

Linda Lowes, sixth author of the present study, is the last author of a 2016 study in Physical Therapy that was retracted months after publication. Its notice reads:

This article has been retracted by the author due to unintentional deviations in the use of the described modified technique to assess plagiocephaly in the study participants, such that the use of the modified technique cannot be defended for the stated purpose in this population at this time.

Califf was a cardiologist at Duke University during the high-profile scandal of researcher Anil Potti at Duke, which led to more than 10 retractions, settled lawsuits, and medical board reprimands. In 2015, he told The Triangle Business Journal:  

I wish I had gotten myself more involved earlier…There were systems that were not adequate, as we stated. … That was a tough one, I think, for the whole institution.

We’ve contacted the FDA for comment, and will update the post with anything else we learn.

Correction 9/21/16 10:44 p.m. eastern: When originally published, this post incorrectly reported that Califf was part of an inspection team that visited the Nationwide Children’s Hospital in Ohio, and attributed quotes from Ellis Unger to Califf. We have made appropriate corrections, and apologize for the error.

Like Retraction Watch? Consider making a tax-deductible contribution to support our growth. You can also follow us on Twitter, like us on Facebook, add us to your RSS reader, sign up on our homepage for an email every time there’s a new post, or subscribe to our daily digest. Click here to review our Comments Policy. For a sneak peek at what we’re working on, click here.