Replies to post #155456 on Biotech Values

[iwfal]

So in a given AD trial, where the futility threshold is the difference between the expected proportion of cognitive decline (obtained from historical data) and a preredetermined accepted reduction of decline (considered as clinically meaningful by experts), interim calculation of cognitive decline below the futility threshold, means the study should go on to completion without modifications and no more?

Possibilities:

a) It looks like you are talking about a single arm trial since you are comparing to historical data? I have never seen anyone attempt to do a futility analysis on a single arm trial so I would need to understand what they are doing better. But I would also make the point, that I am sure everyone on this board understands, that a futility analysis based upon a comparison to historicals would seem to be even more imprecise (i.e. less informative) than a traditional futility analysis in a randomized trial?

b) You also bring up the apparent possibility of modifying the trial based upon the interim. That would make at an adaptive trial and makes the book-keeping more difficult. Again I would need to know more about the trial to say much useful.