Analysts ponder what Sarepta's whirlwind approval means for Biogen—are all bets off?

Biogen biologics plant in Denmark
Biogen’s shares ticked up 1% after-hours on the news of Sarepta Therapeutics' golodirsen approval. (Biogen)

After being hit with an FDA rejection for Sarepta Therapeutics' second Duchenne muscular dystrophy (DMD) drug back in the summer, it looked like a long road, tinged with more than a hint of political intrigue, for it to be approved.

Last night, however, golodirsen was not only approved, completely out of the blue and with no prior communication from the biotech, but got a speedy review at that.

That drug, called VYONDYS 53, is now approved in DMD patients with a particular mutation, less than three months after it was spurned by the regulator over safety concerns (which the company later said it had in fact rectified).

This also all came on the same day Stephen Hahn was confirmed as the next commissioner of the FDA, taking over from the interim commissioner Admiral Brett Giroir, an official at the Department of Health and Human Services, who took over from Ned Sharpless in the fall.

This fleet of changes came amid the unexpected departure of Scott Gottlieb, who left in the spring.

RELATED: FDA surprises Sarepta by spurning its 2nd Duchenne drug

Still following? Good. Now, analysts at Jefferies have scooped up all this context and wonder whether this could be good news for Biogen, and its "it doesn’t work, oh wait it does (if you dig deep enough)" Alzheimer’s disease drug aducanumab.

This drug was on the chopping block earlier this year as it failed to move the needle in Alzheimer’s, but some creative data mining has seen Biogen say it will now, in an amazing about-face, actually try to gun for an FDA approval.

So, does Sarepta’s stunner mean good news for Biogen? “We must ask if the FDA clearly is now capable of making approval decisions on limited data in the CNS group especially when it goes to the higher offices of the FDA as demonstrated by SRPT today ... and whether that is actually a positive read through for BIIB?” Jefferies said in a note to clients late Thursday night.

Jefferies said that while conventional wisdom dictates that the central nervous system division “is tough and harsh under [its chair] Dr. Billy Dunn historically,” at the FDA, “it seems that at least when appealed higher up to the Office of New Drugs—and based on only surrogate measures of "dystrophin" and no functional outcome data, the FDA is even willing to approve SRPT in DMD.”

This begs the question of whether this could translate to an equally unexpected win for Biogen in Alzheimer's “due to similar dynamics.”

The future of that decision will now sit at Hahn’s desk. Either way, Biogen’s shares ticked up 1% after-hours, while Sarepta leapt by 30%.