The rear passenger-side window stopped working for me as well. I could hear the clicking noise when the switch was operated, but the window would not budge. I noticed that the light on the switch would blink twice, in a cyclic fashion.
Following instructions posted elsewhere in this forum, I placed the ignition in the ON position, opened the door with the problem window, pressed down on the switch, then slammed the door shut while holding the window button down. This fixed the problem for me. I think the shock of the door being closed kicks something inside the door back into alignment. Not what I expected from Lexus, but it's an easy fix, so...
Apparently there is a TSB out for installing a spacer of some sort to prevent this problem from occurring, but I'd rather just live with the quirk.