The present invention provides fully human antibodies that specifically bind to human FLT3 within extracellular domains 4 or 5 with high affinity. The invention further provides methods of treating leukemia by administering an effective amount of an antibody either alone or in combination with an anti-cancer agent or treatment including methotrexate.本發明提供以高親和力在細胞外結構域4或5內與人類FLT3特異性結合之完全人類抗體。本發明進一步提供治療白血病之方法，藉由投與有效量之抗體，單獨或與包括甲胺蝶呤之抗癌劑或治療組合。
