FDA advisers reject Sarepta's eteplirsen for DMD

The fate of Sarepta Therapeutics' Duchenne muscular dystrophy (DMD) drug eteplirsen hangs in the balance after advisers to the US Food and Drug Administration (FDA) found it was not effective in disease amenable to exon 51 skipping.

Hundreds of boys with Duchenne and their familes and advocates were at yesterday's meeting in a hotel in Maryland to urge the FDA to approve the drug, desperate for a treatment to halt the cruel wasting disease.

Although the Peripheral and Central Nervous System Advisory Committee's decision is not binding, the FDA often follows the advice of its advisers.

Sarepta's drug is not the only DMD treatment that is struggling to get past the regulator. In January the FDA rejected BioMarin's rival Kyndrisa (drisapersen), another treatment that induces exon skipping to allow formation of a functional protein.

And in February the FDA refused to review PTC Therapeutics' Translarna (ataluren) in nonsense mutation muscular dystrophy, although the drug has been conditionally approved in Europe.

The advisory committee voted 7-6 against a finding that study evidence showed eteplirsen induced production of dystrophin to a level that is reasonably likely to predict clinical benefit.

The committee voted 7-3, with three abstentions, that there was insufficient evidence from the single historically-controlled study (Study 201/202) to show efficacy.

The panel also found that a six-minute walk test may have been biased by subjective decision making by patients, caregivers and healthcare professionals, invalidating a comparison between treatment and control groups.

It was also unswayed by evidence from an ambulatory assessment and further physical performance tests.

Sarepta's shares crashed once trading resumed today, with its stock losing 50% of its value in pre-market trading.  The company says its remains committed to finding a treatment for DMD, but may well have to go back to the drawing board if the FDA confirms the rejection.

The ruling stands in contrast to Europe, where PTC's Translarna gained conditional regulatory approval in August 2014. What's more the drug has received reimbursement approval in the UK with backing from NICE.

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