I'm a little late to this conversation, but interested to know @Joinmelb if you got any clearer response from the drug rep about hair fallout? I have been on Kisqali and Letrozole combo since July 18.It has worked marvellously for me, with very little in the way of side effects. About 6 months in, my hair suddenly became super-thin. It didn't fall out in clumps, but I felt virtually bald in the space of a few weeks. I cut it really short, and I am told now that I have a lot of active hair roots, and baby hair growing through. It does actually seem to be thickening up.
Great news that your PET scans have shown tumours to be stable. I've also had really positive results- in fact my dosage has been reduced to 2 tablets per day, 2 weeks/1 week off. This eliminates my horrible third week of fatigue, and my skin feels good again.
Has your onc considered reducing the dosage, in light of stable results?
Best wishes!