Is your Doctor thinking about her next move? Looking for a clinical trial? Or just waiting and seeing what will happen? Usually, these are the reasons I have found my Dr. to wait, and it's super annoying. However, if you don't like it, then be the squeaky wheel. They have other patients, as well. It's not like they are always sitting around thinking of your case. Unless you are popping up in their MYCHART, be nice when you do this. Of course, try to become their friend. When you see them, ask them how their day was. Figure out why they are so stressed, then when you see them again, ask them about what was stressing them out last time. You know, treat them as human beings. Then they might start to forgive some of your craziness that will go down over the years and pay them back for when you need them.
Now about your case, Maybe she thinks you're ready to come off it how good was your scan?
I am assuming you are hormone positive and HER2negative, as I am. The next drug that replaced IBRANCE for me was Verzinio, but there may be a few others. The Drug class is (endocrinen therapy) You should do some research on it and then come to your doctor and ask them if there is a reason they haven't put you on a second endocrine therapy.