Dendreon Corp fka DNDNQ

[io_io]

Sam - I frankly think the odds are modest, certainly far less for the interim look than for the final look.


First of all, by far the most popular way of planning interim looks is the O'Brien-Fleming method (can you guess who Fleming is ? not sure, but I believe that's HIM - hey maybe this was his motive ?!? ha-ha). In that case, the p-value will be an awful lot closer to p=0.01 than to p=0.025, in fact use p=0.01 to be on the safe side.

Second, of any cancer therapy, this is not like chemo, whcih ahs generally rapid results, but it acts slow. Therefore initially the sickest patients will die in equal numbers on both arms - this not only prevents a good hazard ratio from developing, but will comprise a large portion of the 180 events.

Third, the censored numbers will be large and fairly equal (advantage given only by the corresponding survival advantage), again limiting chances of success.

At a rough guess, you would probably need 35%-40% more deaths (maybe 105 v 75 might be nice round numbers to compare with 9901 & 9902a) on the control arm to get your p-value here.


My conclusion is that it's a high hurdle (I mean that so few cancer drugs hit these interim looks anyway, and once again, this is not fast-acting chemo) and there will be easier meat between now and then.