Toinv -
Absolutely agree Don has an unfortunate weak spot for designing the next trial around favourable, but potentially misleading, outcomes of post hoc subgroup analyses of the last trial, risking the next one being underpowered. But Don doesn't seem to understand the problem.
If it's true BP offered to fund the bigger 5 year study, perhaps they also felt that that's the only sound scientific way to proceed. So it was either that, and be confident you've got the power calculations right, or nothing. Let's hope for the best!
Very frustrating.