Palbociclib: First CDK4/6 Inhibitor in Clinical Practice for the Treatment of Advanced HR-Positive Breast Cancer.

Palbociclib is the first inhibitor of the cyclin-dependent kinases (CDK) 4 and 6 to be introduced into clinical practice. Preclinical investigations led to its clinical development in advanced hormone receptor (HR)-positive breast cancer. To date, 2 significant clinical trials have been fully published. In this article, the results of these trials and their clinical relevance for the management of HR-positive advanced breast cancer are discussed.