An orally bioavailable, ATP-competitive, reversible small-molecule Aurora kinase inhibitor with potential antineoplastic activity. Aurora kinase inhibitor PF-03814735 binds to and inhibits Aurora kinases A and B, which may result in the inhibition of cellular division and proliferation in tumor cells that overexpress these kinases. Aurora kinases are serine-threonine kinases that play essential roles in mitotic checkpoint control during mitosis.