"Thus it will be a repeat of the Rett trial requiring yet again...

"Thus it will be a repeat of the Rett trial requiring yet again another longer term, bigger dose, larger number study to reach criteria necessary for approval."

So that would be a phase 3 trial then???

I don't see the problem. The phase 2 needed to show safety and some proof of efficacy. It did just that. Now they can plough more resources into the phase 3(s) with the knowledge that there's a higher probability of success.

The phase 2 trial was a big commitment for the families of Retts sufferers to make. A long time away from home, to trial something unknown and maybe be on the placebo. To make the treatment time longer would probably have put off many participants.

The phase three(s) will be different however, as we now have a "proven" product.

As for fragile X, it is my understanding that the treatment time in the trial is twice as long as in the Retts trial. Also the mouse results had three times more impact on fragile X mice as apposed to Retts mice.

But if you are concerned about trial validity, watch for the monster TBI phase 2 results. That'll really show whether our drug is effecting the brain. And that trial is robust enough to gain accelerated approval.

Cheers