Drug Development

Another old drug looks for a second coming at the FDA, this time for Duchenne MD

So far, drugs that try to address the root cause of Duchenne muscular dystrophy have had to travel a rocky road at the FDA. But regulators are now hustling up a review of a new treatment — new to the US at least— that will try to do what a lineup of well financed biotechs and pharma companies have failed at.

Marathon Pharmaceuticals put their DMD candidate deflazacort through a Phase III study, and it says the drug provided evidence of improving the muscle strength of boys, letting them do better at a variety of physical tasks, like sitting up or walking. On Wednesday, the FDA provided priority review status for the drug when it accepted the application for review, setting up an accelerated February PDUFA deadline on whether it should be used to treat DMD boys with the lethal disease.

Unlike the exon-skipping technology that BioMarin tried, and failed, to get approved in the US — and Sarepta continues to push hard on — deflazacort is a simple systemic steroid used for decades outside the US.

It’s sold by Shire in the UK, for example, as Calcort in 6 mg tablets and used to treat a variety of chronic autoimmune conditions like rheumatoid arthritis. You can buy it in Canada or an online pharmacy for about a buck a pill. But because it’s never been approved in America, where other steroids have been available for those same conditions, it gets the full regulatory treatment.

The FDA has played its part. Aside from giving deflazacort priority review status, cutting 4 months off the usual 10-month process, the agency has provided fast track status, an orphan drug designation and rare pediatric disease status for the drug to hustle it along and extend market protection to Marathon. Rare pediatric disease approvals have been used to gain priority review vouchers under a special FDA program designed to spur the development of important new drugs. And they have fetched hundreds of millions of dollars.

Deflazacort has won some key support from patient advocacy groups, who also applauded Marathon’s decision to provide the steroid for free in an open access program. Valerie A. Cwik, MD, Executive Vice President and Chief Medical and Scientific Officer for the Muscular Dystrophy Association, had this to say for the treatment:

The Duchenne community would greatly benefit from widespread and reliable access to a treatment option with the potential to delay disease progression. We are all too familiar with the challenges that children and adults with Duchenne and their families face, and we’re hopeful that an FDA approval of deflazacort would be one of the first of many treatments for Duchenne.

Marathon’s Phase III trial didn’t use deflazacort alone. It added a low dose of the glucocorticoid to prednisone, looking to balance a better impact on strength that deflazacort offered with the immunosuppressant.

So now the FDA can have a look at a combination of two well known anti-inflammatories. It can approve deflazacort/prednisone as a new drug for DMD, opening up a market of desperate patients. And it will likely spur a fresh outburst over what patients pay for old drugs that can be purchased for a fraction of the price in another country.

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Sr. Manager, Regulatory Affairs, CMC
CytomX Therapeutics San Francisco, CA
Marketing Associate - Demand Generation
Catalytic Data Science Charleston, SC
Associate Principal, Life Sciences Partnerships
Flatiron Health New York City or San Francisco

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