The US Food and Drug Administration (FDA) has approved the corticosteroid deflazacort (Emflaza, Marathon Pharmaceuticals) to treat patients age 5 years and older with Duchenne muscular dystrophy (DMD), the agency said today.
"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," according to an FDA news release. Deflazacort will be available in tablets and oral suspension.
"This is the first treatment approved for a wide range of patients with Duchenne muscular dystrophy," Billy Dunn, MD, director, Division of Neurology Products, FDA Center for Drug Evaluation and Research, said in the release. "We hope that this treatment option will benefit many patients with DMD."
DMD is a rare genetic disorder that causes progressive muscle deterioration and weakness. The first symptoms typically appear between age 3 and 5 years and worsen over time. The disease primarily affects boys. Estimates are that DMD occurs in about 1 of every 3600 male infants worldwide.
The effectiveness of deflazacort was demonstrated in a clinical study of 196 boys with DMD aged 5 to 15 years.
At week 12, patients receiving deflazacort had improvements in muscle strength compared with those taking a placebo, which was maintained at week 52.
In a separate trial of 29 male patients lasting 104 weeks, deflazacort demonstrated a numeric advantage over placebo on an assessment of average muscle strength. Patients receiving deflazacort also appeared to lose the ability to walk later than those treated with placebo.
Adverse effects related to deflazacort mirror those seen with other corticosteroids, the FDA said. The most common side effects include facial puffiness (cushingoid appearance), weight gain, increased appetite, upper respiratory tract infection, cough, pollakiuria, hirsutism, and central obesity.
Less common side effects include problems with endocrine function, increased susceptibility to infection, elevation in blood pressure, risk for gastrointestinal perforation, serious skin rashes, behavioral and mood changes, decrease in the density of the bones, and vision problems (such as cataracts).
Deflazacort was given fast-track designation and priority review by the FDA. The drug also received orphan drug designation, which provides incentives to assist and encourage the development of drugs for rare diseases.