A monoclonal antibody directed against the ephrin receptor A2 (EphA2), with potential antineoplastic activity. Upon administration, anti-EphA2 monoclonal antibody DS-8895a selectively binds to cells expressing the EphA2 receptor. This blocks EphA2 activation and EphA2-mediated signaling. In addition, DS-8895a may activate an immune response against EphA2-expressing tumor cells. The cell-surface receptor EphA2, a member of the ephrin family of receptor tyrosine kinases (RTKs) that are involved in mammalian development, is overexpressed by a variety of cancer cell types and plays an important role in tumor growth.