AZD 1152 is an orally bioavailable prodrug of AZD 1152-HQPA, a selective inhibitor of Aurora kinase B (IC50= 0.36 nM).1AZD 1152 is converted to AZD 1152-HQPA in plasma. Inhibition of Aurora B results in disruption of spindle checkpoint functions and chromosome alignment, resulting in inhibition of cytokinesis followed by apoptosis.2,3AZD 1152 inhibits tumor xenograft growthin vivo.4,5