Thanks for the detailed response. I understand your point that if 011 works, there's a 90% chance that it will show up as stat sig at full analysis and a 57% chance at interim, when only 2/3 of the events will have occurred. What if 011 doesn't work -- is the probability that that will be known at interim and the trial halted for futility also 57%? Sorry if that's a dumb question. My statistics is pretty rudimentary.
Everything you said about how survival is likely to be longer than in the P2 due to the introduction of new second-line drugs and about when the interim is likely to occur makes sense to me.