molecules of the month

5. The Pfizer CDK2/4/6 inhibitor PF-60873600 is orally bioavailable with Ki values of 0.09 nM, 1.3 nM, and 0.16 nM for CDK2, CDK4, and CDK6, respectively, with lower activities against CDK1 (4.5 nM) and CDK9 (20 nM). PF-06873600 entered in Ph. I/IIa in 2018 against HR+ HER2- breast and ovarian cancers. Control of the cell cycle through selective inhibition of CDK4/6 has proven beneficial in the treatment of breast cancer (e.g. palbociclib, ribociclib), and CDK2 has recently emerged as a therapeutic target in multiple tumor types. Targeting additional cell cycle CDK isoforms may allow treatment of additional tumor types and overcome resistance to selective CDK4/6 inhibitors. Nonselective CDK inhibitors, however, have a history of failure in clinical trials due to…