I am considering going on the trial, my Oncologist suggested it.
I did have some rather unpleasant side effects on chemo though so will have to investigate it further as a lot of the side effects listed are what I experienced on chemo. Still it is a different drug, so maybe it will have a different effect.
In my situation I think I might give it a try and I can always come off it if it doesn't agree with me.
If you google Palcociclib, there is a very good fact sheet that comes up that is helpful.