SAR156497 is an exquisitely selective Aurora A, B, and C inhibitor with in vitro and in vivo efficacy with IC50 = 0.5 nM (Aurora A); 1 nM (Aurora B incenp); 3 nM (Aurora C incenp) respectively SAR156497 combines high in vitro potency with satisfactory metabolic stability and limited CYP 3A4 and PDE3 inhibition. In vitro, SAR156497 displayed high antiproliferative activity on a large panel of tumor cell lines without correlation with any particular genetic signature or Aurora kinases expression. It induced significant modulation of Aurora A and Aurora B biomarkers (p-Aurora A and pHH3, respectively) and cell polyploidy, as expected from Aurora A B inhibitors.