Sarepta’s eteplirsen spurned as European regulators turn thumbs down on controversial Duchenne MD drug
Sarepta’s approval for eteplirsen — or Exondys51 — in the US remains one of the most controversial OKs in FDA history, earning a rare label that says the biotech has yet to produce evidence the drug works.
But lightning won’t strike twice on the regulatory pathway for this biotech.
The biotech reported Thursday afternoon that the CHMP is prepping a negative vote, barring the drug from the continent. And Sarepta shares immediately tumbled 5% in after-market trading.
The drug, which has a solid set of supporters in the DMD community, is getting snubbed despite the Europeans’ acceptance of PTC Therapeutics’ rival drug, which has failed repeated pivotal studies. But in DMD, regulators have a tendency to make things up as they go along, frequently bending the rules to accommodate a passionate group of patients and parents — or not. PTC has been repeatedly slapped down by the FDA, even after Janet Woodcock overruled a host of agency insiders with her insistence on approving eteplirsen.
Sarepta CEO Doug Ingram had this to say:
Unfortunately, the CHMP’s trend vote was negative. Based on discussions with CHMP representatives, it is our understanding that the CHMP did not conclude that eteplirsen is ineffective for exon 51 amenable patients, but rather that Sarepta has not yet met the regulatory threshold for conditional approval, in part due to the use of external controls as comparators in the studies. Sarepta plans to file for re-examination and will request that a Scientific Advisory Group (SAG), which is made up of DMD and neuromuscular specialists, be convened to provide expert guidance and insight into, among other things, the validity of the external controls used and the importance of slowing pulmonary decline in patients with DMD.
Hoping to take some of the sting out of the news, while disappointing some analysts with its Q1 performance, Sarepta also announced a deal to partner with Myonexus Therapeutics on its work developing gene therapies for Limb-girdle muscular dystrophies. Sarepta paid $60 million upfront and offered $45 million more in milestones for the deal, which also provides the biotech with a buyout option at proof-of-concept.
“Myonexus and its focus on gene therapy using the AAVrh.74 vector to treat forms of LGMD aligns brilliantly with our vision to emerge as one of the most meaningful global precision genetic medicine companies by focusing on the use of genetic medicine to improve the lives of those with rare fatal diseases,” said Ingram in a prepared statement.