Ann: Neuren presents at Rettsyndrome.org 2016 Research Symposium-NEU.AX, page-3

The conference poster gives an insight into the challenges in trying to determine efficacy and in trying to bring a drug to market.

You only have to look at failed FXS trials where the parents were sure the drug had a positive effect but the trial was aborted because the stats didn't show it.

Here we have to measurement criteria, one which shows efficacy (MBA) and one that doesn't (CSS). Without looking up the details of the paper describing MBA specifically, naively you'd say that the MBA is more comprehensive and less likely to "miss things out."

Recall also that at the AGM, Treagus said (my italics):

"In relation to progress on the key regulatory matters, we have had a series of interactions with the FDA and I am pleased to report that we have now reached agreement on the construct of the primary outcome measure considered acceptable for use in a pivotal registration study. The measure, which is derived from the Motor Behavior Assessment used by clinicians in the Rett syndrome natural history study, has been carefully designed to capture potential improvement in the core signs and symptoms of Rett syndrome. "

A look at the CSS vs MBA results in the poster show just how important that discussion would have been.

Someone recently commented about trialling trofinetide for autism. The problem there is this problem of measurement: given autism is such a broad condition anyway, and kids can have good or bad days, how do you accurately measure efficacy? The answer is: large numbers, careful clinical measurement, expensive trials.

Although the TBI letdown took the wind out of the sails for the acute side of the target market, for chronic conditions all the boxes are ticked so far: positive trial results for Rett and FXS.