GAC,

The decision to stop the Aducanumab trial was made as follows:

"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."

As we know, RVX chose not to do a FA on apabetalone.  As far as i know, it isn't really the job of the DSMB to do an statistical analysis of efficacy - that comes at the end of the study.  The DSMB might evaluate efficacy if it found itself in the difficult position of having some safety issues arise while at the same time seeing differences between the placebo and drug arms of a trial that made it appear that the drug was working.  I think that the DSMB board for apabetalone might have suggested that a FA be done at some prior point if there were absolutely no differences between the placebo and apabetalone groups, but I don't know whether the DSMB would perform the FA or an outside group would be contracted to do that.  In short, because the trial is blinded to everyone else, I don't think the DSMB would 'spill any beans' on efficacy unless it had to deal with safety issues or unless the expense of continuing an a futile trial made them call for a (or perform their own) FA.

Jupe