On Feb. 25, the US Food and Drug Administration (FDA) granted accelerated approval to casimersen (Amondys 45) for the treatment of Duchenne muscular dystrophy (DMD) in patients amenable to skipping exon 45. It is the fourth exon-skipping, disease-modifying drug to treat DMD, the most common childhood form of muscular dystrophy. The drug is administered by intravenous . . .