What happened with the approval of Exondys 51 in 2016?
An FDA advisory panel voted 7-6 against the drug, the review team recommended rejection, and the drug increased dystrophin to only about 0.28% of normal — yet the head of FDA's drug centre overruled both, and two reviewers resigned.
Exondys 51 (eteplirsen) was approved in September 2016 under accelerated approval based on a study of just 12 boys. An FDA advisory panel had voted 7-6 against it and the review team recommended rejection. The drug increased dystrophin only to about 0.28% of normal levels on average, while reviewers believed more than 10% might be needed for clinical impact.
Janet Woodcock, head of the FDA's drug centre, overruled the reviewers. The agency's acting chief scientist concluded her involvement had upended the normal review process and possibly marked the first time a centre director had overruled both a review team and an advisory committee on effectiveness; Commissioner Robert Califf deferred to Woodcock anyway, and two review team members resigned. The drug was priced around $300,000 a year. European regulators rejected it in 2018.