P2a had unexpected efficacy. The three trials going on now should be final proof of concept.
I would contend that the P2a data is far far far from proven efficacy. Those trying to show a theoretical underpinning (unique MOA) to those results seem to agree because if the results stood on their own there would be no reason to need that underpinning.
What is offered in support of that underpinning? None of the preclinical evidence offered by AVXL supports anything more than a generic S1R action for 2-73. I'm not aware of any other preclinical evidence in existence and no one has offered such on this board. You feel that P2a results are sufficient to indicate a unique/advantageous MOA that would therefore underpin P2a results and therefore provide reasons to counter the many doubts raised concerning the P2a results. Is it even necessary to point out the logical flaws of this line of argument?