Patent No. 594950 Disclosed is the use of an anti-EphA3 antibody in the manufacture of a medicament for treating a myeloproliferative disorder in a patient, wherein the patient has myeloproliferative disorder cells that express EphA3 on the cell surface and wherein the anti-EphA3 antibody (i) activates EphA3 and (ii) induces ADCC. Also disclosed is a method of monitoring the efficacy of treatment of a patient having a myeloproliferative disorder with EphA3+ myeloproliferative cells, wherein the myeloproliferative disorder is AML or MDS, the method comprising: providing a sample previously obtained from the patient comprising myeloproliferative disorder stem cells and/or blast cells from the patient following a therapeutic treatment for the myeloproliferative disorder and detecting expression of EphA3 on the myeloproliferative disorder stem cells and/or blast cells.
