Bispecific antibody format

Abstract

[Problem] Provided is a bispecific antibody with a novel format that retains high binding affinity to both antigens, and can be efficiently produced in a commercial production process. [Means for Solution] A bispecific antibody comprising two heavy chains, two first light chains, and two second light chains, in which the heavy chains each comprise a first heavy chain variable region, a CH1 region, a first linker, a second heavy chain variable region, and a heavy chain constant region in order from the amino terminus side; the first light chains comprise a first light chain variable region and a first light chain constant region; the second light chains comprise a second light chain variable region and a second light chain constant region; the first heavy chain variable region and the first light chain variable region form a first antigen binding site; the second heavy chain variable region and the second light chain variable region form a second antigen binding site; and the first antigen binding site and the second antigen binding site recognize different antigens each other.