ribociclib,palbociclib
novartis,pfizer
['congrat', 'ribociclib', 'palbociclib']
 congrats,beautiful investigator initiated study (#maintain) of maintenance cdk4/6i with ribociclib &amp; switch et at #asco22. as 87% pts had prior palbociclib does this actually prove a benefit of switch cdk4/6i and et? or do you feel the prior cdk4/6i doesn t matter?