Ilorasertib (ABT-348) is an ATP-competitive multitargeted kinase inhibitor with IC50s for inhibiting binding Aurora B (7 nM), C (1 nM), and A (120 nM), and also inhibits RET tyrosine kinase, PDGFRβ, and Flt1 with IC50s of 7 nM, 3 nM and 32 nM. Ilorasertib is an ATP-competitive multitargeted kinase inhibitor with IC50 for inhibiting cellular autophosphorylation of Aurora B (13 nM), C (13 nM), and A (189 nM). In addition to targeting Aurora kinases, Ilorasertib is a potent inhibitor of the VEGFR and PDGFR kinase families and, to a lesser extent, the Src family of cytoplasmic tyrosine kinases. Ilorasertib induces a concentration-dependent increase in the extent and number of two NSCLC cell lines exhibiting polyploidy. The potency for inducing this response (EC50 = 5 and 10 nM). Ilorasertib shows antiproliferative activity against BCR-ABL expressing CML cells and cells expressing the gleevec-resistant BCR-ABL T315I mutation (IC50 = 47 and 260 nM). Ilorasertib (25 mg/kg, s.c.) leads to an inhibition of histone H3 phosphorylation in circulating tumor cells obtained from an engrafted leukemia model. Ilorasertib inhibits the VEGF response with a potency (ED50 = 0.2 mg/kg i.v.) in a uterine edema model. Ilorasertib (20 mg/kg, p.o.) inhibits the growth of established tumors and causes regression of advanced tumors in human xenograft models. Ilorasertib demonstrates significant antitumor efficacy in both solid and hematological xenograft models after intravenous, mini-pump or parenteral once-weekly dosing.