- Major U.S. health insurer Anthem will not cover Sarepta Therapeutic's newly approved treatment for Duchenne muscular dystrophy, judging the drug to be "investigational and not medically necessary" in a medical policy bulletin posted on the company's website last week.
- Anthem is the first large insurance company to decide against covering Exondys 51 (eteplirsen), which received a conditional — and controversial —approval from the Food and Drug Administration last month. Other insurers, such as UnitedHealth Group have opted to cover the drug, according to Reuters.
- Sarepta's stock, which soared on news of the drug's approval, fell by over 6% in Friday trading. Exondys 51, which will cost approximately $300,000 per patient per year, is the first disease-modifying drug okayed to treat the muscle-wasting disease.
Anthem did not look favorably on the clinical evidence Sarepta had mustered as proof of Exondys 51's efficacy.
"Ultimately, eteplirsen secured the FDA's approval based on an increase in dystrophin seen in the skeletal muscle of some boys treated with the drug; however, uncertainty exists regarding whether the small observed increase in dystrophin will confer a clinically meaningful benefit," Anthem said in the notice.
The FDA granted accelerated approval to Exondys 51, meaning its decision was based on improvement in a surrogate endpoint — dystrophin production — rather than measured clinical benefit. Although the FDA was generally in agreement that increased production of dystrophin, a key protein missing in DMD patients, was a reliable surrogate endpoint, senior staff were divided on how much of an increase was needed to reliably predict clinical benefit.
Sarepta's clinical evidence, based on data collected from a small group of patients, showed treatment with Exondys 51 appeared to increase dystrophin production. The effect, however, was small, and FDA reviewers questioned Sarepta's handling of its new drug application for approval of the DMD drug.
Anthem picked up on many of these concerns in its review of the drug, finding some of the limitations to be significant enough to cast doubt on the "reliability of dystrophin levels as a surrogate endpoint for clinical efficacy."
Given the controversy over the FDA's approval, along with the dearth of other options for DMD patients, insurer coverage decisions have taken on greater importance. Anthem's decision to not cover Exondys 51, while so far the only insurer-related setback, represents yet another hurdle for Sarepta and DMD families. It also underscores the shakiness of eteplirsen's clinical evidence, which will continue to be under the microscope as Sarepta moves forward with confirmatory trials.