For the ongoing phase III study, PTC narrowed enrollment to DMD kids 7 or older and those with baseline six-minute walk tests of 350 meters or less. These are the kids who seemed to benefit more from ataluren in the phase IIb study.
It's not a crazy thesis. Sarepta also enrolled older kids with more advanced disease in its eteplirsen phase II study for exactly the same reasons. While I'm generally skeptical of conclusions derived from post-hoc sub-group analyses, PTC's theory makes sense.
Where ataluren falls short -- and why the ongoing phase III study in nonsense mutation DMD carries a high risk of failure -- is the absence of dystrophin production.
Ataluren, by design, should boost the production of functional dystrophin, the protein that supports muscle function.
@adamfeuerstein nice piece. Do you think they'll get an RTF letter? $VNDA— Juan P. Serrate, DVM (@JPZaragoza1) June 19, 2013Vanda's FDA submission for tasimelteon has a lot of problems, as I documented Wednesday, but almost all are clinical review issues and therefore unlikely grounds for the agency to slap down a Refuse-To-File letter. The FDA has plenty of reasons to reject tasimelteon after a proper review.