From the Aucentra Therapeutics web site:So it looks like David...

From the Aucentra Therapeutics web site:

So it looks like David already had some involvement with the company prior to this appointment. Interestingly, his Bio here doesn't mention Race at all, which means that either it was recently amended to reflect his resignation (though I don't think that is the case as I checked the cached version and that is identical), they neglected to mention his involvement with Race, or his involvement pre-dates his time at Race (i.e. he has been involved for some time). I'm leaning towards the latter.

Although it's not a good look that David has left Race, based on the fact it appears he was already involved with Aucentra, it's not exactly something that has come out of the blue. Who knows, maybe they reached a point and made him an offer he literally couldn't refuse, or maybe he's heavily invested there (privately) already, or can see more opportunity for recognition there given the strong team at Race that surrounded him, or maybe he's happy having a hedge with a few hundred thousand Race options and wants to try something else that may be more interesting/suitable for whatever reason.

On the converse side, regardless of how well things look for a company, there are always egos that clash and personalities that don't get along - perhaps there were some irreconcilable differences. Or maybe Race were unhappy with David's performance (e.g. slow recruitment of the EMD AML trial) and he could see the writing on the wall and Aucentra was a fall-back option. Also, with the goal to start European trial sites soon, it's possible the upcoming workload was something David didn't feel he wanted at this point in his life - I've worked jobs involving a lot of overseas travel and out of hours phone calls and it's a great opportunity as a young person but I couldn't imagine doing it now that I have a family.

Obviously the first thought when we see unexpected news like this is that the wheels have fallen off somewhere, however I think there's plenty of possible rational explanations for this change that don't imply a negative outcome for Race.