Antibodies, humanized antibodies, resurfaced antibodies, antibody fragments, derivatized antibodies, and conjugates of same with cytotoxic agents, which specifically bind to, and inhibit A class of Eph receptors, antagonize the effects of growth factors on the growth and survival of tumor cells, and which have minimal agonistic activity or are preferentially devoid of agonist activity. Said antibodies and fragments thereof may be used in the treatment of tumors that express elevated levels of A class of Eph receptors, such as breast cancer, colon cancer, lung cancer, ovarian carcinoma, synovial sarcoma and pancreatic cancer, and said derivatized antibodies may be used in the diagnosis and imaging of tumors that express elevated levels of A class of Eph receptors. Also provided are cytotoxic conjugates comprising a cell binding agent and a cytotoxic agent, therapeutic compositions comprising the conjugate, methods for using the conjugates in the inhibition of cell growth and the treatment of disease, and a kit comprising the cytotoxic conjugate are disclosed are all embodiments of the invention. In particular, the cell binding agent is a monoclonal antibody, and epitope-binding fragments thereof, that recognizes and binds the A class of Eph receptors.
