In the Q&A for the 9/25/15 presentation, Don said something to the effect of the length of trial being determined by the estimated time for screening/recruitment and estimated 18 months to get 250 events. BETonMACE is an event driven trial, so from what I understand the trial will be stopped once 250 is reached. However, without knowing the true status of patient recruitment and not knowing the event rate in either the control or RVX-208 treated patients, one can't for sure conclude anything about drug efficacy from the trial length.

BETonMACE is designed to have 80% power to detect a 30% RRR. 10.5% event rate expected in placebo arm and 7.47% event rate in RVX-208 arm at 18 months (1st patients treated for 24 months, last patients treated for 12 months, average of 18 months), based upon the similar patient population in the EXAMINE trial. However, patient population in BETonMACE may have higher or lower average event rate. Don said something to the effect of they won’t be doing any interim analysis/sneak peaks of BETonMACE other than safety data by data safety monitoring committee.

So from what I understand total study duration 2.5 to 3 years depending upon recruitment and overall event rate. In my opinion, these factors are going to affect trial length much more than drug efficacy.

BearDownAZ