I would think leading up to the "period" of time when Merck will likely unblind the results, you could probably see a "run-up" like you did in some garbage names like GNVC and NVLT (see charts)...there was speculation (and terribly incorrect, at that), that because the "delays" in the trial results, it must have meant that the drug was working longer (it didn't pan out so well for those shareholders).
I don't know why the Ariad trial is extending a few months longer than anticipated - which is why I have been very consistent in my belief that the patient population in this trial makes it a crap-shoot.