The invention provides an antibodies that bind to KDR with an affinitycomparable to or higher than human VEGF, and that neutralizes activation ofKDR. Antibodies include whole immunoglobulins, monovalent Fabs and singlechain antibodies, multivalent single chain antibodies, diabodies, triabodies,and single domain antibodies. The invention further provides nucleic acids andhost cells that encode and express these antibodies. The invention furtherprovides a method of neutralizing the activation of KDR, a method ofinhibiting angiogenesis in a mammal and a method of inhibiting tumor growth ina mammal.
