17. Exondys 51

FDA sign

Active ingredient: eteplirsen
Disease: Duchenne muscular dystrophy (DMD)
Peak sales estimate: $1 billion-plus
Approved: Sep. 19
Company: Sarepta Therapeutics

The Scoop: This is easily the most controversial FDA approval of the year. The agency approved the drug based on a surrogate biomarker endpoint: the dystrophin increase in skeletal muscle observed in some Exondys 51-treated patients. But the company did not present any trial data demonstrating clinical benefit to patients. The FDA noted bluntly in the approval, “A clinical benefit of Exondys 51, including improved motor function, has not been established.” This was an accelerated approval and the agency is requiring a follow-up clinical trial to demonstrate clinical benefit, which could include improved motor function. DMD is a devastating disease that’s accompanied by ongoing muscle wasting and an early death typically in the patient’s twenties or thirties. Internal FDA documents that surfaced after the approval make it clear the decision was contested heavily within the agency, but that the ultimate decision was to approve the drug in order to facilitate ongoing research rather than end it. Sarepta priced Exondys 51 at about $300,000 per patient per year with an estimated 1,200 to 1,500 boys in the U.S. expected to potentially benefit. Insurers are already starting to balk at the price, particularly given that there’s no clinically proven efficacy. -- Stacy Lawrence

17. Exondys 51