FDA okays first DMD drug

Abstract

Sarepta Therapeutics has won FDA approval of Exondys 51 (eteplirsen), the first drug sanctioned for treating Duchenne muscular dystrophy. Afflicting one in every 3,500 to 5,000 boys, DMD is a fatal genetic disorder characterized by progressive muscle deterioration. Approved under an accelerated program for drugs that treat life-threatening diseases, Exondys 51 is being made available on the basis of initial clinical data. “We eagerly await learning more about the efficacy of this drug through a confirmatory clinical trial that the company must conduct,” says Janet Woodcock, director of FDA’s Center for Drug Evaluation & Research. DMD is caused by mutations in the gene encoding for dystrophin, a protein that keeps muscle cells intact. Sarepta’s phosphorodiamidate morpholino oligomers prevent the reading of faulty gene regions during mRNA processing. This “exon skipping” method enables production of a truncated, but still functional, protein. Up to 80% of DMD patients have genotypes open to