"Is there any reason they couldn't disclose what they are to investors? I'm just wondering if one or more of A B C could be viewed as a negative?"

I am sure many will see the changes as a negative. Those who take the negative view need to ask themselves:

Do you think US/FDA involvement is a good thing? I am guessing most would say yes.

If yes, then would you rather have a completely separate US BETonMACE trial or a modification of the current trial? I am guessing most would rather modify the current trial because this is a faster (no need for second US trial), cheaper (unlikely to need another 2400 patient trial), and more efficient (one single trial for clinical readout, FDA/EMA filing) route to US drug approval.

If you think that modifying the current trial is better, then how do you expect to include US patients without modifying the current trial? At this stage of the game (over 20 months into the trial and over 70% enrolled) it is totally reasonable that the FDA is going to want the US cohort to meet certain requirements for patient number/MACE event/drug treatment duration.

BearDownAZ