Palbociclib and Ribociclib are FDA approved drugs that target cyclin dependent kinases CDK4 and CDK6 to treat breast cancer. Herein, we conducted a cheminformatics analysis of a large set of their analogs. The study highlights (i) several clusters of similar compounds with excellent inhibitory profiles, (ii) their shared CDK-ligand intermolecular interactions as predicted by 3D docking, and (iii) key dynamic interactions shared by highly active CDK4/6 inhibitors.