If Provenge has a clinical benefit, then it should easily beat 0.025 or 0.03 at the final look with a large trial of over 500 patients and 360 death events.
This is probably where you and I differ inre how much alpha to assign to the interim. I think there is a reasonable chance that the true efficacy is near HR=1.4 in this patient population. And at 360 events the trial is not overly powered (it is in the 80 pct powered region for raw log rank <0.05 - and stratified randomization/CR will improve on that but still under 90% powered.) I would still consider 1.4 (or even 1.3) as a clinically relevant HR given the therapautic index - but the trial is underpowered for such HRs.