US20260201049
2026-07-16
Chemistry; metallurgy
C07K16/2875
The invention concerns multispecific antibodies, which are engineered proteins capable of binding two or more antigens. These antibodies are created through various techniques, including cell fusion, chemical conjugation, and recombinant DNA methods. The invention also includes methods for producing these antibodies, pharmaceutical compositions containing them, and their potential applications.
Multispecific antibodies have been developed in several formats, such as tetravalent bispecific antibodies and others that do not retain the traditional antibody core structure. These formats use linkers to fuse antibody components, which can lead to issues like immune responses against the linker, instability, and increased immunogenicity. The goal is to develop antibodies that closely resemble naturally occurring ones, with minimal deviations from human sequences, while retaining functions like complement-dependent cytotoxicity.
One challenge with existing methods, such as quadroma technology, is the production of mispaired byproducts, which require complex purification. The "knob-into-hole" technology addresses this by modifying the CH3 domains to promote the correct pairing of antibody heavy chains. However, this method requires identical light chains, limiting its application for creating tri- or tetraspecific antibodies. The invention proposes a new approach to reduce side products and improve the purity and stability of multispecific antibodies.
The invention describes a multispecific antibody comprising light and heavy chains from two different antibodies. In this design, specific domain replacements and amino acid substitutions are made to improve the antibody's properties. For instance, the constant domain CL of the second light chain is replaced with the constant domain CH1 of the second heavy chain, and vice versa. Specific amino acid substitutions are also introduced to enhance stability and reduce unwanted byproducts.
A method for preparing these multispecific antibodies involves transforming host cells with vectors containing nucleic acids encoding the specified light and heavy chains. This process ensures the production of antibodies with the desired specificity and reduced byproduct formation. The approach aims to enhance the purity and thermal stability of the resulting antibodies, making them more suitable for therapeutic applications.