Re: your comment that it is notable that almost all of the seperation occurs during the third year: Wouldn't this be what you would be looking for? And wouldn't it be bad for the drug's prospects if all the seperation was in year 1 and/or 2, then by year three there was no seperation or the curves actually crossed?
As a layman looking at these curves, I am not overly impressed, but I do come away with the impression that Provenge is probably somewhat effective in helping long term survival. What am I missing?