DMD: Sarepta Will Pursue Accelerated Approval for Eteplirsen and Conduct Additional Trials

Access to eteplirsen may come in 2015; the company will conduct a confirmatory trial of eteplirsen and two additional trials of the drug

Article Highlights:
  • In a May 13, 2014, webcast, Sarepta Therapeutics summarized its plans for eteplirsen and other experimental exon-skipping compounds it has in development to treat Duchenne muscular dystrophy; eteplirsen targets exon 51 of the dystrophin gene and could provide a treatment for 13 percent of the DMD population.
  • Sarepta will apply to the U.S. Food and Drug Administration for accelerated approval of eteplirsen, which could be granted as early as 2015 but will require a confirmatory study for full approval; an accelerated approval designation allows patients to have access to the drug prior to full approval.
  • By early 2015, Sarepta hopes to open trials of its compounds targeting dystrophin exons 45 and/or 53.
by Margaret Wahl on May 19, 2014 - 2:33pm

Update (May 27, 2014): Sarepta has acquired a manufacturing facility in Massachusetts to enhance its ability to produce investigational exon-skipping therapies DMD. In a May 22 press release, Sarepta CEO Chris Garabedian said, "While we scale up to address the potential U.S. commercial demand for our lead product candidate eteplirsen in the event of an approval next year, the addition of internal resources willl enhance our ability to advance the development of our broader exon skipipng platform and explore the potential of our technology platform in other therapeutic areas."


original story:

Sarepta Therapeutics, developer of experimental Duchenne muscular dystrophy (DMD) drug eteplirsen, says it will move forward as quickly as possible with a new drug application for this compound, as well as with a large-scale, confirmatory trial, two additional trial of eteplirsen, and trials of at least one other experimental drug of this class.

Eteplirsen is an exon-skipping compound that targets exon (section) 51 of the dystrophin gene, coaxing muscle cells to leave out (skip) that section of genetic instructions and produce functional, though short, dystrophin protein molecules. It's been estimated that 13 percent of boys with DMD — those with dystrophin mutations near exon 51 — can potentially benefit from skipping exon 51.

Sarepta summarized its current plans for eteplirsen and other exon-skipping drugs for DMD in a May 13, 2014, webcast for the DMD community, now archived on the company's website; and in a May 8, 2014, press release.

Summary of the May 13 webcast

On the May 13 webcast, Sarepta made the following statements:

  • The U.S. Food and Drug Administration (FDA), reversing an earlier decision, will consider an accelerated approval pathway for eteplirsen.
  • If the FDA grants an accelerated approval status for eteplirsen based on the phase 2b,12-participant trial results, the drug could become available to patients in 2015, although Sarepta would be required to conduct a confirmatory study to obtain full approval for the drug.
  • Sarepta is planning a confirmatory trial of eteplirsen for the third quarter of 2014, using a "historical" control group instead of a placebo group for comparison to an eteplirsen-treated group. Historical control groups comprise previously studied patients.
  • The confirmatory trial of eteplirsen will include boys with DMD who are between 7 and 16 years old, can walk a minimum distance, and have dystrophin mutations potentially treatable by skipping exon 51.
  • In addition to the large-scale, confirmatory trial of eteplirsen in ambulatory (walking) boys, the company will test the drug in two other populations beginning in the fourth quarter of 2014: boys with DMD who are less than 7 years old, and those who can no longer walk a minimum distance and are 20 years old or younger.
  • By early 2015, Sarepta plans to open placebo-controlled studies of its exon-skipping compound targeting exon 45 and/or its compound targeting exon 53 in North America and Europe.
  • The company plans to begin an open-label (no placebo group) study of its compound to target exon 53 in Europe and the United Kingdom in the third quarter of 2014.
  • Details of these and other upcoming trials, including study sites and criteria, are not yet available but will be posted on and Sarepta's Let's Skip Ahead site when they are. Sarepta urges families to provide information and sign up for updates on the Let's Skip Ahead site under "Join Us."
  • Families can send email to Sarepta at, and can call the company toll-free at (855) 363-7547, which is (855) DMD-SKIP.

MDA's role in developing exon skipping

MDA has supported laboratory development of exon skipping since the 1990s and continues to support refinement of this strategy through grants to Steve Wilton at Murdoch (Australia) University and others. In addition, MDA provided supplemental funding for the phase 2 trial of eteplirsen conducted at Nationwide Children's Hospital in Columbus, Ohio. In addition, the Association's DMD Clinical Research Network's studies of disease progression in children under age 3 and in those who have stopped walking are likely to provide crucial information for the design of exon-skipping trials in these groups.

For more information

To learn more, see DMD: Exon-Skipping Timeline and Exon Skipping in DMD: What Is It and Whom Can It Help.

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