You are missing the time factor from your equation. Not all patients have been dosed for the same period of time. I believe the ~10% to 12% event rate is based on control patients being dosed for 18 months. You need to think of it in terms of duration of patient dosing. Based on the enrollment and predictions, mid year is still the earliest that I would expect the 125 events to trigger the futility analysis, in my opinion. 

BearDownAZ