MDA welcomes FDA approval for muscular dystrophy drug

The Food and Drug Administration (FDA) has approved Emflaza (deflazacort; Marathon) tablets and oral suspension for the treatment of Duchenne muscular dystrophy (DMD) in patients aged 5 years and older. DMD is caused by an absence of dystrophin, a protein that helps keep muscle cells intact. At Week 12, patients in the Emflaza group had improvements in clinical assessment of muscle strength across a number of muscles vs. patients taking placebo. Emflaza secured approval for all Duchenne Muscular Dystrophy patients ages 5 and older, while Sarepta's Exondys 51 is approved only for a specific subset for DMD patients who have a confirmed mutation of the dystrophin gene amenable to exon 51 skipping. In Canada and other countries around the world, deflazacort has been used for years to treat DMD and the pills or oral suspensions range from about $1,000 to $2,000 a year for patients.

In a separate trial of 29 male patients lasting 104 weeks, deflazacort showed a numeric advantage over placebo on an assessment of average muscle strength. Adverse effects associated with Emflaza include facial puffiness, weight gain, increased appetite, upper respiratory tract infection, cough, extraordinary daytime urinary frequency, unwanted hair growth, and excessive fat around the stomach. The Wall Street Journal article quoted Christine McSherry, founder of the Jett Foundation, who said she pays $1600 a year for deflazacort from a British online pharmacy but now that the FDA has approved deflazacort for the United States, the British pharmacy will no longer ship it to America.

Other less-common AEs include problems with endocrine function, increased susceptibility to infection, hypertension, the risk of gastrointestinal perforation, serious skin rashes, behavioral and mood changes, decreased bone density, and vision problems, such as cataracts.

"We now have a treatment option for kids and adults with Duchenne, which is a major advance for the community", said MDA chief medical and scientific officer Valerie Cwik. Those with the disease usually lose the ability to walk in their teens and have a life expectancy around 25 to 30 years. It primarily affects boys, occurring in about one out of every 3,600 male infants worldwide.

Patients with DMD typically do not live past their 20s or 30s, according to the FDA. The voucher is meant to incentivize drug companies to develop treatments for rare diseases.