UPDATED: The FDA decides that it can’t decide yet on Sarepta’s eteplirsen

The long-playing drama surrounding the fate of Sarepta’s Duchenne muscular dystrophy drug eteplirsen will continue past this week.

The agency, according to Sarepta, wants more time to complete the review and “internal conversations” on the matter, forcing it to miss one of the most closely watched agency deadlines of the decade. 

“The FDA has communicated that they will continue to work past the PDUFA goal date (Thursday) and strive to complete their work in as timely a manner as possible,” the company reported.

Investors who had been waiting it out took the indefinite delay as a sign of hope for a surprise approval, driving up the company’s shares ($SRPT) by 25%. This is the second delay at the FDA. A winter storm forced the cancellation of the originally scheduled panel review early this year, derailing the agency's timeline.

There had been growing speculation in the market that the FDA might just extend its deadline again, with rumors circulating that the agency wanted to help investigators recruit more patients for an ongoing study and perhaps look for additional data to use in their decision. 

The recent FDA panel review for eteplirsen drew a legion of advocates and powerful allies in Congress and beyond who demanded that the FDA push through an approval based on a tiny study involving 12 boys suffering from the terminal illness. Agency reviewers, though, dug their heels in, insisting that Sarepta had never offered convincing evidence that the drug helped these patients at all. And while there was no reason to believe the drug is dangerous, they were also quick to note that even that is hard to tell based on such skimpy data. 

Quite a few people in the industry sided with the argument against an approval, saying that a decision in its favor would set a dangerous precedent. And a number of analysts, including RBC's Simos Simeonidis, were betting that the odds weighed heavily in favor of a CRL.

"Today's news is a clear incremental positive for Sarepta: not only was the worst case scenario, i.e. a CRL averted, but this extension by FDA, which appears open-ended and not the standard 3-month type, buys more time for the company's supporters and the DMD patient community to exert additional pressure to FDA," Simeonidis noted today. "However, based on the FDA's analysis of the data and the precedent a potential approval would set, we continue to believe that the chances of an approval are limited, and we continue to expect a Complete Response Letter (CRL) for eteplirsen."

Art Krieg, who served a stint as CSO at Sarepta, says he can't determine exactly what the delay might indicate.

"I'm not sure how to read it to be honest," he tells me in an email. "If they were simply going to reject it, seems like it would've been an easy decision. Of course, I suppose you could say that about granting accelerated approval. More delays!"

Sarepta has taken investors on one of the longest running roller coaster rides now playing out in biotech. Over the past three years it has repeatedly stoked the hopes of patients and supporters with the argument that regulators could be won over by a small study that purported to show a distinct advantage for the drug group compared to the historical data it assemble in lieu of a placebo arm. 

But over the course of the first half of this year the agency slapped that argument down twice with harsh analyses that illustrated its clear frustration that the company had failed to follow its repeated advice to perform a larger, controlled study that could provide clear insights on the drug’s ability to help patients, or not. A majority of FDA advisers agreed with the insiders' assessment, voting against an accelerated approval in the face of a large crowd of Sarepta sympathizers.

In the meantime, the FDA has shot down two potential rivals, from PTC Therapeutics  ($PTCT) and BioMarin ($BMRN), insisting that neither biotech had made their case. PTC’s application wasn’t even accepted for review. And that makes eteplirsen the last hope that patients will have in the near future--whether it works or not.

- here's the release

Related Articles:
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Sarepta shrinks as execs wait for FDA's decision on Duchenne drug
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