IgG-like Bispecific Antibody Development
There are two chain mis-pairing challenges in production of heterodimeric IgG-like bispecific antibody. One is to facilitate heterodimerization of two distinct heavy chains and prevent homodimerization of two identical heavy chains. The second is to have correct pairing of cognate heavy and light chains. An efficient strategy to overcome these challenges is to use knobs-into-holes (KIH) technology to favor heterodimerization of two different heavy chains and combine with a common light chain, based on the widely accepted fact that the affinity and specificity of an antibody is mainly defined by the heavy chain, and it can be maintained when an antibody has a non-cognate light chain.
Genekine uses a versatile approach to directly generate common light chain bispecific antibodies by using yeast surface display of heterodimeric IgG-like bispecific antibody. In this approach, two heavy chains from existing antibodies to two different antigens are heterodimerized by KIH technology, and introduced into human naïve and synthesized light chain libraries. Then the resulting bispecific antibody libraries are displayed on yeast cell surface in heterodimeric IgG-like bispecific antibody format. The library can be simultaneously selected by fluorescence-activated cell sorting (FACS) against two target antigens to isolate common light chains that, in combination with two heavy chains, retain their binding affinity for two antigens. This straightforward approach can efficiently isolate common light chains for various combinations of two existing heavy chains. It generates functional and developable IgG-like bispecific antibodies, which exhibit high affinities in the nanomolar range and have the similar biochemical and biophysical properties to parental antibodies.