Description: IC50 Value: 4 nM (IC50) for Aurora A, and below or equal to 13 nM (IC50) for Aurora B [1]. SCH 1473759, a novel sub-nanomolar Aurora A/B inhibitor. Aurora kinases are required for orderly progression of cells through mitosis, and inhibition of these kinases by siRNA or small molecule inhibitors results in cell death [2]. in vitro: Asynchronous cells required 24-h exposure to SCH 1473759 for maximal induction of >4 N DNA content and inhibition of cell growth. However, following taxane- or KSP inhibitor-induced mitotic arrest, less than 4-h exposure induced >4 N DNA content. This finding correlated with the ability of SCH 1473759 to accelerate exit from mitosis in response to taxane- and KSP inhibitor-induced arrest [2]. in vivo: SCH-1473759 showed efficacy and target engagement in A2780 human tumor xenograft model in mouse, and also acceptable pharmacokinetic dosing in dog, monkey and rodents, on target efficacy, as well as a safety profile in dogs[1]. Clinical trial: N/A