Shares in Sarepta Therapeutics surged more than 30% in after-hours trading yesterday on news that it can finally set in motion filing its Duchenne muscular dystrophy drug in the US.

The Cambridge, Massachusetts-based biotech said following a meeting with US Food and Drug Administration it can now initiate a rolling New Drug Application for its top candidate eteplirsen to facilitate regulatory review. 

Non-clinical and CMC components of the NDA will be filed by the end of this week, with the final component to be submitted by the middle of the year, the firm noted.

Investors will be breathing a huge sigh of relief given that the drug has encountered much turbulence on its regulatory pathway, reportedly culminating in strained relations between the firm and the regulator, a request by the FDA for more data on the drug last October, and resignation of chief executive Chris Garabedian earlier this year.

And it seems new chief executive Edward Kaye is keen to improve relations. “The FDA said this was the best meeting they’ve had with Sarepta,” Kaye said in a telephone interview with Bloomberg, adding “it was validation that we could turn it around. Rather than arguing with them on what they needed, we made sure we gave them exactly what they asked for.”