An orally bioavailable, highly selective small molecule inhibitor of the serine/threonine protein kinase Aurora A kinase with potential antineoplastic activity. Auora kinase inhibitor MLN8054 binds to and inhibits Aurora kinase A, resulting in disruption of the assembly of the mitotic spindle apparatus, disruption of chromosome segregration, and inhibition of cell proliferation. Aurora A localizes in mitosis to the spindle poles and to spindle microtubules and is thought to regulate spindle assembly. Aberrant expression of Aurora kinases occurs in a wide variety of cancers, including colon and breast cancers. Check foractive clinical trials using this agent.