“This phase 2 clinical trial is an exploratory study and was not...

“This phase 2 clinical trial is an exploratory study and was not intended to be powered to obtain statistical significance.”

The phrase "exploratory study" just means that PAR are unsure what results to expect from this study and are simply using it to gather information about how iPPS works in the body. The "powered" phrase means that there were not enough participants in each cohort to expect the results to be statistically significant, so today's results are impressive in light of this.

In terms of the cohort selected, the initial pool of candidates are decided based on the inclusion / exclusion criteria and ultimately those selected for the trial are based on a combination of 1) those who come forward, 2) those who match for age, sex, disease stage etc and 3) the block randomisation strategy used. While it is possible to enrich for a particular subset of patients, sometimes it ultimately comes down to an algorithm which decides who can participate in a trial or not.

".....does this show we achieved broadly similar (or even slightly better) P&F results via WOMAC in a cohort not intended to be powered for statistical significance?"

I think today's results were slightly better than the previous P2b trial, although I would not read too much into it due to the low sample numbers, but instead I, myself, am interpreting the P&F results as consistent with all the other P&F results. Aside from the trial being randomised, placebo controlled and double blind, something else the FDA really likes is consistency. Today's results go some way to explain how iPPS works in this body, which is something else the FDA really likes. So we're definitely on the right track.