Bispecific antibodies are a class of antibody molecules that can simultaneously recognize and bind to two different antigens or antigen epitopes. Compared to traditional monospecific antibodies, bispecific antibodies have unique advantages in fields such as tumor immunotherapy, autoimmune diseases, and infectious diseases.
The design of bispecific antibodies is complex, requiring them to bind to two different antigens simultaneously while ensuring stability, ease of manufacturing, and good biological activity. To achieve these goals, scientists have designed various structures, which can be mainly classified into the following categories:
IgG-like Bispecific Antibody
The CrossMab structure solves the issue of chain mismatch by exchanging the light chain or CH1 domain, retaining the complete IgG structure. This ensures a longer half-life in the body and allows it to perform various Fc-mediated functions. The Knobs-into-Holes (KiH) technology introduces "knobs" and "holes" mutations in the Fc region, ensuring that different heavy chains combine correctly.
Fragment-Based BsAbs
BiTE is composed of two single chain variable fragments (scFv) linked together, acting like a "bridge" connecting T cells (CD3) on one end and tumor antigens (such as CD19) on the other. DART stabilizes the structure with special disulfide bonds, making the antibody more stable and binding more tightly to antigens.
Multivalent Bispecific Antibody
TandAb has four antigen-binding sites and an exceptional ability to bind to target cells. It is particularly suitable for the dense microenvironment of tumor cells, making it more effective in fighting tumors.
Updated: Apr 24, 2025
