Marathon Pharmaceuticals, LLC, a biopharmaceutical company developing treatments for rare diseases, announced the New Drug Applications (NDA) for the investigational drug deflazacort have been accepted for filing and granted Priority Review by the US Food and Drug Administration (FDA). The NDAs (one for immediate-release tablet formulations and one for an oral suspension formulation) request approval for deflazacort for the treatment of patients with Duchenne muscular dystrophy (DMD), the most common and most severe form of muscular dystrophy.

The FDA’s Priority Review status is reserved for drugs that offer significant improvements over existing options or provide a treatment for a condition for which no approved treatment currently exists, and shortens the agency’s review time from 10 months to a goal of six months. A decision on the application is anticipated in February 2017 based on the Prescription Drug User Fee Act (PDUFA). Deflazacort previously received Fast Track status, Orphan Drug designation and Rare Pediatric Disease status from the FDA.

“This is an important milestone for Marathon but more importantly, for the Duchenne community,” said Jeff Aronin, chief executive officer, Marathon Pharmaceuticals. “Today, a large number of those living with Duchenne who could potentially benefit from deflazacort do not get it simply because they do not have access. If deflazacort is approved, our goal is to work closely with the community and to make deflazacort widely available to Duchenne patients in the United States.”

The NDA filing included data from studies showing that deflazacort improved muscle strength and other functional outcomes in patients with Duchenne regardless of genetic etiology and in one of the studies ambulation status.

“The Duchenne community would greatly benefit from widespread and reliable access to a treatment option with the potential to delay disease progression,” said Valerie A. Cwik, M.D., executive vice president and chief medical and scientific officer for the Muscular Dystrophy Association. “We are all too familiar with the challenges that children and adults with Duchenne and their families face, and we’re hopeful that an FDA approval of deflazacort would be one of the first of many treatments for Duchenne.”

During the FDA review process, Marathon is making deflazacort available to US patients, at no cost, through Access DMDTM, an expanded access program (EAP) operating under FDA authorization. Patients, families and physicians can learn more about AccessDMD, including a list of clinical sites participating in the program, by visiting www.AccessDMD.com or calling 1-844800-4DMD (4363).

Deflazacort, an investigational drug, is a glucocorticoid with anti-inflammatory and immunosuppressant properties. Deflazacort is not currently approved in the United States for any indication. Versions of deflazacort are available in some countries outside the United States where it is approved for a number of indications, but not for Duchenne. If approved, deflazacort will be among the first commercially available treatments indicated for Duchenne in the United States. As of the date of the NDA filing acceptance, there is no cure for Duchenne and currently no FDA-approved treatment.

Based on data contained in the NDAs and in published clinical studies, it appears that deflazacort may be an important treatment option for patients with Duchenne, if approved by the FDA. In one of the pivotal, randomized, double-blind, placebo controlled and active comparator studies that followed 196 patients with Duchenne, deflazacort met its primary endpoint of improved muscle strength versus placebo at 12 weeks. Improvements in muscle strength continued through the end of study at Week 52.

Side effects that could occur with Deflazacort use include: weight gain, increased appetite, facial puffiness or Cushingoid appearance, unwanted hair growth, skin redness, and headache.

Other less common but important side effects include: a decrease in the density of the bones (osteopenia) or fragility of the bones (osteoporosis) which may lead to fractures, acne, stomach upset or irritation to the stomach lining, cataracts (which can impair vision), increased susceptibility to infection, sugar intolerance and aggravation of diabetes, elevation in blood pressure, behavioral and mood changes, effects on growth and development such as short stature.

Deflazacort use is not recommended for patients who have a systemic fungal infection or are allergic to deflazacort or any of the inactive ingredients in deflazacort, have had recent or ongoing infections or have recently received a vaccine or are scheduled for a vaccination.

Duchenne muscular dystrophy (DMD) is the most common and most severe form of muscular dystrophy. It affects mainly boys and young men, with an incidence of approximately 1 in 5,000 live male births. The disease is marked by progressive muscle weakening and wasting, leading ultimately to the inability to walk by the teen years or earlier, and severe respiratory and cardiac complications. Few patients live into their thirties.