Marathon Pharmaceuticals Submits New Drug Application to FDA for Deflazacort to Treat DMD

MarathonSocialLogo HPMarathon Pharmaceuticals announced today it has submitted a New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA) for the investigational drug deflazacort for the treatment of people with Duchenne muscular dystrophy (DMD). The FDA has 60 days to determine whether the NDA is complete and acceptable for filing.

Deflazacort, a glucocorticoid, works as an anti-inflammatory and immunosuppressant. In a pivotal study involving 196 participants with DMD, results showed that treatment with deflazacort improved muscle strength. Side effects reported to date for the drug include cushingoid appearance (puffiness and weight gain), abnormal hair growth, skin redness, swelling of the nasal passages or upper respiratory infection, irritability, and cataract formation.

In the United States, deflazacort is considered an investigational therapy, as it has not been approved by the U.S. Food and Drug Administration (FDA) for any disorder. Versions of the drug are approved in other countries, but not for DMD. If approved, deflazacort will be among the first commercially available treatments for DMD in the U.S.

As deflazacort makes its way through the regulatory review process, an expanded access program, ACCESS DMD, is ongoing at medical centers across the United States and provides deflazacort to patients with DMD free of charge. To learn more about ACCESS DMD, including a list of clinical sites participating in the program, visit, or call 1 (844) 800-4363.

MDA has a long history of supporting research and clinical study into the effects of corticosteroids, including deflazacort, in DMD, with studies to determine the drug’s mechanism of action, drug effects, side effects and best dosing regimen.