FDA: 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. 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 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. An overall stability in average muscle strength was maintained
through the end of study at week 52 in the deflazacort-treated patients.
In another trial with 29 male patients that lasted 104 weeks,
deflazacort demonstrated a numerical advantage over placebo on an
assessment of average muscle strength. In addition, although not
statistically controlled for multiple comparisons, patients on
deflazacort appeared to lose the ability to walk later than those
treated with placebo.
The side effects caused by Emflaza are
similar to those experienced with other corticosteroids. The most common
side effects include 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
Other side effects that are less common include problems
with endocrine function, increased susceptibility to infection,
elevation in blood pressure, risk of gastrointestinal perforation,
serious skin rashes, behavioral and mood changes, decrease in the
density of the bones and vision problems such as cataracts. Patients
receiving immunosuppressive doses of corticosteroids should not be given
live or live attenuated vaccines.
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 sponsor is receiving a rare pediatric disease priority review voucher
under a program intended to encourage development of new drugs and
biologics for the prevention and treatment of rare pediatric diseases. A
voucher can be redeemed by a sponsor at a later date to receive
priority review of a subsequent marketing application for a different
product. This is the ninth rare pediatric disease priority review
voucher issued by the FDA since the program began.
Emflaza is marketed by Marathon Pharmaceuticals of Northbrook, Illinois.