The new medicine, eteplirsen, is targeted at the 13% of those boys whose muscular dystrophy is caused by a certain type of mutation.

FORBES: In A First, An Experimental Drug May Help Boys With Muscular Dystrophy

One big question: would the limited data Sarepta has so far collected from a very small clinical trial of its drug eteplirsen, a treatment for Duchenne muscular dystrophy that is caused by a very specific type of mutation, be enough to warrant filing with the Food and Drug Administration and perhaps even gain approval?

FORBES: A Key Exchange On Sarepta Therapeutics' Promising Muscular Dystrophy Drug