Abstract: The present invention provides novel human fms related tyrosine kinase 3 (FLT3) antigen binding proteins, such as antibodies, having improved FLT3 binding affinity, and/or anti-tumor activity. The FLT3 antibodies of the invention were generated by mutation of a parent FLT3 antibody and tested in in vitro in binding assays as well as in vivo in a mouse tumor model and in human patient tumor samples. The antibodies of the invention are provided as monospecific constructs or in a bispecific FLT3xCD3 antibody format and show excellent target affinity and/or tumor cell killing. The present invention also relates methods for producing the antigen binding proteins of the invention as well as nucleic acids encoding them, vectors for and host cells for their expression. The invention further relates to methods of treating or diagnosing a disease such as leukemia using an FLT3 antigen binding protein (ABP) of the invention.

Abstract: The present invention provides novel human fins related tyrosine kinase 3 (FLT3) antigen binding proteins, such as antibodies, having improved FLT3 binding affinity, and/or anti-tumor activity. The FLT3 antibodies of the invention were generated by mutation of a parent FLT3 antibody and tested in in vitro in binding assays as well as in vivo in a mouse tumor model and in human patient tumor samples. The antibodies of the invention are provided as monospecific constructs or in a bispecific FLT3×CD3 antibody format and show excellent target affinity and/or tumor cell killing. The present invention also relates methods for producing the antigen binding proteins of the invention as well as nucleic acids encoding them, vectors for and host cells for their expression. The invention further relates to methods of treating or diagnosing a disease such as leukemia using an FLT3 antigen binding protein (ABP) of the invention.

Abstract: The present invention provides novel human fins related tyrosine kinase 3 (FLT3) antigen binding proteins, such as antibodies, having improved FLT3 binding affinity, and/or anti-tumor activity. The FLT3 antibodies of the invention were generated by mutation of a parent FLT3 antibody and tested in in vitro in binding assays as well as in vivo in a mouse tumor model and in human patient tumor samples. The antibodies of the invention are provided as monospecific constructs or in a bispecific FLT3×CD3 antibody format and show excellent target affinity and/or tumor cell killing. The present invention also relates methods for producing the antigen binding proteins of the invention as well as nucleic acids encoding them, vectors for and host cells for their expression. The invention further relates to methods of treating or diagnosing a disease such as leukemia using an FLT3 antigen binding protein (ABP) of the invention.