I imagine that PRM would tell us as they would likely strike up an agreement first - although the details of that could be kept very vague?
New uses for old drugs and more specific uses for withdrawn drugs should very much still be a possibility - its easy to forget about the potential for proteomics and it is still very early day!
Vioxx for example could be reignited if a simple screen for 'at risk' patients could be used.
The same applies for clinical trials. I'm expecting a commercial AD test to be incorporated quickly into trials for drugs that need enhancement of patient populations as it is an easy way to save costs of trial sizes and increases the likelihood of demonstrating efficacy - but reduces the potential for (on-label) use in a wider patient population (but what good is a huge patient pool if you cant get approved!)
There are something like 200 Alzheimer's drugs in development for example. I'd reckon that most of these dont have a chance without careful selection of a more appropriate patient pool ie. those with pre-symptomatic AD..... thats where PRM could fit in?!....