Eteplirsen (brand name Exondys 51) is a medication to treat, but not cure, some types of Duchenne muscular dystrophy (DMD), caused by a specific mutation.

Eteplirsen was developed by Steve Wilton, Sue Fletcher and colleagues at the University of Western Australia and commercialized by Sarepta Therapeutics.

[6] The following adverse events were observed in at least 10% of people who received eteplirsen in trials: vomiting, contusion, excoriation, arthralgia, rash, catheter site pain, and upper respiratory tract infection.

[citation needed] Eteplirsen is a morpholino antisense oligomer which triggers excision of exon 51 during pre-mRNA splicing of the dystrophin RNA transcript.

[11] This modified dystrophin protein produced by eteplirsen may cause a less severe form of dystrophinopathy, much like Becker muscular dystrophy.

By increasing the quantity of an abnormal, but potentially functional, dystrophin protein, the objective is to slow or prevent the progression of DMD.

This required randomized, controlled trials showing effectiveness of a meaningful clinical outcome, such as the ability to function in daily life.

Sarepta and patient groups wanted to use the standard of historical controls, personal testimonies, and the presence of altered dystrophin in the body.