Bear just a point:

"The decision to stop the trials is based on results of a futility analysis conducted by an independent data monitoring committee, which indicated the trials were unlikely to meet their primary endpoint upon completion. The recommendation to stop the studies was not based on safety concerns."(bolding added)

The above quotation does not state an interim futility analysis. Interim seems to imply that it's a planned interim (scheduled) analysis. Is it possible that IDMB did it on their own initiative seeing that they saw no hope of success for aducanumab? 

By the same token can we also deduce that on a positive note that the BOM, IDMB would have also halted the BOM Phase III trial if they saw no appreciable difference in narrow MACE events and in efficacy with the apabetalone arm as compared with the placebo arm, which they have not. :o)

just saying...Koo