CDK4/6/1 Inhibitor (Crozbaciclib) is a type of CDK4/6 inhibitor (IC50s: 3 and 1 nM). CDK4/6 inhibitor is a class of compounds used for the treatment of some types of hormone receptor positive, HER2-negative breast cancer, which can block the process of breast cancer cell division and reproduction.

CDK4:3 nM, CDK4:3 nM , CDK6:1 nM , CDK6:1 nM

CDK4/6/1 Inhibitor is an anti-proliferative agent that arrests the U87MG cell line exclusively in G1 (IC50=15.3 nM in the anti-proliferation assay). U87MG cells exposed to varying concentrations of CDK4/6/1 Inhibitor for 24 hours show a dose-related increase in G1 arrest, and a significant increase in the percentage of cells in G1 is found in as little as 13.72 nM of CDK4/6/1 Inhibitor.[1]

In an orthotopic xenograft mouse model of glioblastoma multiforme, CDK4/6/1 Inhibitor (3.125 to 50 mg/kg) has tumor growth inhibition values ranging from 62% to 99%, and no significant body weight loss is observed. The increase in life span based on the median survival time of vehicle-treated animals in mice administered a dose of 50 mg/kg is significant at 162%.[1]