FDA approves Emflaza for Duchenne muscular dystrophy

NORTHBROOK, Ill. — The U.S. Food and Drug Administration today approved Emflaza (deflazacort) tablets and oral suspension to treat patients age 5 years and older with Duchenne muscular dystrophy (DMD), a rare genetic disorder that causes progressive muscle deterioration and weakness.

Emflaza is a corticosteroid that works by decreasing inflammation and reducing the activity of the immune system. It is marketed by Northbrook-based Marathon Pharmaceuticals.

Corticosteroids are commonly used to treat DMD across the world. This is the first FDA approval of any corticosteroid to treat DMD and the first approval of deflazacort for any use in the United States.

“This is the first treatment approved for a wide range of patients with Duchenne muscular dystrophy,” said Billy Dunn, M.D., director of the Division of Neurology Products in the FDA’s Center for Drug Evaluation and Research. “We hope that this treatment option will benefit many patients with DMD.”

DMD is the most common type of muscular dystrophy. DMD is caused by an absence of dystrophin, a protein that helps keep muscle cells intact. The first symptoms are usually seen between 3 and 5 years of age and worsen over time. The disease often occurs in people without a known family history of the condition and primarily affects boys, but in rare cases it can affect girls. DMD occurs in about one of every 3,600 male infants worldwide.

People with DMD progressively lose the ability to perform activities independently and often require use of a wheelchair by their early teens. As the disease progresses, life-threatening heart and respiratory conditions can occur. Patients typically succumb to the disease in their 20s or 30s; however, disease severity and life expectancy vary.

The FDA granted this application fast track designation and priority review. The drug also received orphan drug designation, which provides incentives to assist and encourage the development of drugs for rare diseases.

The effectiveness of deflazacort was shown in a clinical study of 196 male patients who were 5 to 15 years old at the beginning of the trial with documented mutation of the dystrophin gene and onset of weakness before age 5. At week 12, patients taking deflazacort had improvements in a clinical assessment of muscle strength across a number of muscles compared to those taking a placebo.