Eteplirsen

Duchenne muscular dystrophy (DMD) is a degenerative muscle disease that occurs in young boys. It can be hereditary or the result of a mutation in the gene that produces the muscle-related protein dystrophin. The most common type of muscular dystrophy, DMD is usually fatal by the time the patient reaches 30 years. No cure has been found for any form of muscular dystrophy.

There is a glimmer of hope, however. Sarepta Therapeutics (Cambridge, MA) developed a drug called eteplirsen (trade name Exondys) for treating (but not curing) some mutations that cause DMD. This past September, The US Food and Drug Administration awarded “accelerated approval” to eteplirsen.

FDA’s decision is controversial because critics in the pharmaceutical industry suggest that tests on the drug were inadequate and that there is reason to believe that the drug is ineffective. In addition, eteplirsen treats only a small fraction of DMD patents; and Sarepta estimates that the drug’s cost would be ≈US$300,000 per year.

The controversy may represent a cautionary tale for FDA. Detractors argue that the agency succumbed to pressure from advocacy groups and families of DMD victims. The balance between scientific rigor and humanitarian considerations is indeed a delicate one.