PROTACs suppression of CDK4/6, crucial kinases for cell cycle regulation in cancer.

PROTACs based on two selective, FDA approved, CDK4/6 inhibitors were formed. One of them, based on palbociclib, potently initiates degradation of these CDK proteins, and suppresses phosphorylation of retinoblastoma protein (Rb) leading to cell cycle arrest. These PROTACs are active at nanomolar concentrations, and appear to be the first for CDK4/6.