Long story short, it's a good news-bad news scenario.
The good news is that this is now a one-horse race and that horse's name is eteplirsen. If the DMD treatment gets approved, it's obviously better to be the only drug on the market than to have competition.
The bad news is that DEMAND-III "highlights it is difficult to design a clinical trial in this patient segment" and presents some uncertainty regarding "what the FDA requirements [will be] for [eteplirsen] clinical trials."
Also: Stifel is apparently out with a positive call for SRPT