Replies to post #5306 on Dendreon Corp fka DNDNQ

[iwfal]

The CEGE CEO also staed at their CC, that Vital 1 also used the conservative O'Brien Fleming rules to allocate its interim alpha p value.

Conservative shmaservative. The O'Brien Fleming boundary is designed so that the alpha for the final look is as close to 0.05 as possible so that the adjudicators don't have to make the politically challenging, but epistemologically correct, call to reject if the final p value measured is, say, 0.04 and the alpha assigned to that look was only 0.01.

As a result of this desire to avoid politically challenging calls the Fleming/O'Brien boundary assigns little alpha to intermediate looks. My guess is somewhere between 0.003-0.005 when there is only one interim and it is at 1/2 of final events.

Clark