This article is the result of a round-table discussion organised by ESMO Open in Vienna in December 2017. Its purpose is to discuss the background and advances in the evidence regarding cyclin-dependent kinase 4/6 inhibitors (palbociclib, ribociclib and abemaciclib) in the treatment of metastatic and early-stage breast cancer and to explore what the key open research questions are and next steps should be.
Keywords: CDK4/6 inhibitors; HR-positive breast cancer; breast cancer; endocrine resistance; endocrine therapy; metastatic breast cancer.