Emflaza, a tablet and oral suspension corticosteroid, has been approved by the Food and Drug Administration for the treatment of Duchenne muscular dystrophy in patients aged 5 years and older.

The agency’s Feb. 9 announcement notes that similar corticosteroids have been used around the world to treat Duchenne muscular dystrophy (DMD), but this is the first to gain approval in the United States. Emflaza (deflazacort) works by decreasing inflammation and immune system activity.

The drug received fast track status, priority review, and orphan drug designation from the FDA. It will be marketed in the United States by Marathon Pharmaceuticals.

DMD is the most common form of muscular dystrophy but is still rare, occurring in about 1 in 3,600 male infants worldwide. One study found that patients taking deflazacort had some improvements in muscle strength at 12 weeks, compared with those taking placebo, and maintained muscle strength stability through 52 weeks. A longer-term study showed that patients who took deflazacort had better average muscle strength than did those taking placebo and suggested that deflazacort helped prolong patients’ ability to walk.

Side effects experienced by patients taking Emflaza are similar to those associated with other corticosteroids, such as facial puffiness (cushingoid appearance), weight gain, increased appetite, upper respiratory tract infection, cough, extraordinary daytime urinary frequency (pollakiuria), unwanted hair growth (hirsutism), and excessive fat around the stomach (central obesity).

In the FDA’s announcement, Billy Dunn, MD, director of the Division of Neurology Products in the FDA’s Center for Drug Evaluation and Research, said, “We hope that this treatment option will benefit many patients with DMD.”