The repercussions of the FDA’s accelerated approval of eteplirsen for Duchenne muscular dystrophy (DMD) in 2016 on the basis of a trial of 12 boys with the condition continue, write authors of an op-ed article. “Although the FDA initially set a November 2020 deadline for eteplirsen’s manufacturer to complete a clinical trial determining whether the drug has clinical benefit, the company will not complete the trial until 2024 or later,” the authors write. “The relationship between levels of truncated dystrophin, the muscle protein studied in eteplirsen’s pivotal trial, and clinical outcomes remains uncertain.” Eteplirsen was initially marketed at a price of $300,000 per year and is estimated to be selling now for more than $1 million per year.
“More than 6 years after the FDA granted accelerated approval to eteplirsen on the basis of a small change in an unvalidated surrogate measure, [antisense oligonucleotide] drugs for DMD have multiplied in the marketplace, but none have been proven to offer clinical benefit to patients,” the authors conclude. “The regulatory history of these drugs illustrates several trends that trouble drug approval and reimbursement decisions in the United States, including thorny issues surrounding the use of surrogate measures in accelerated approvals, pricing considerations, and the role of political pressure in regulators’ decision making. The FDA’s review of eteplirsen set a problematic precedent for the accelerated approval pathway and helped inspire some recent policy changes to that program—with more such changes needed.”