Rare diseases sometimes put families in desperate and tragic situations. These families are supported by charities that often campaign with a great deal of passion and determination, but sometimes at the risk of jeopardising their cause.

The US Food and Drug Administration (FDA) has approved eteplirsen, a new drug to treat patients with Duchenne muscular dystrophy (myopathy) which affects boys. It was authorised on the basis of three trials involving 12 and 13 patients. The FDA panel of experts, however, found "major flaws in the design and conduct of clinical trials using eteplirsen" making it impossible to use most of the results as robust evidence for granting a marketing authorisation. However, flying in the face of the experts' opinion, the Director of the FDA issued the marketing authorisation because she did not "want to hold" those flaws "against the patients" who urgently require access to this new drug. A demand reinforced by the company's advertising.

One year's treatment will cost an average of $300 000 per patient.

This price level for poorly evaluated orphan drugs is coming under increased criticism. A former chairman of the French Economic Committee for Health Products (CEPS) said that "orphan diseases take up a considerable slice of spending and are too costly" for the public purse.

In reality, marketing authorisations issued on the basis of a rudimentary clinical evaluation and the astronomical price of these drugs are likely to work against patients' interests. 

©Prescrire 1 January 2018

"Drugs for rare diseases: baseless approvals" Prescrire Int 2018; 27 (189): 3. (Pdf, free).