As others have noted, he has exercised 75,000 shares in the last month, and only sold 11,800. And as said people have noted, the optics of said action are not good.
It's also an interesting development considering that he would have access to the "blinded data". I recall that some of us have been told by the company's executives that said "blinded data" looked incredible. I recall someone posted specifically about this last summer (link):
"Blinded data is also pointing in the right direction for the other end points – eGFR data “looks stunning, seeing amazing increases, unheard of”, cognitive improvement (MoCA test) data also encouraging (looking for >1.5 units improvement; anything <18 is considered Alzheimers)."