| abstract |
The present invention relates to the technical field of antibody drugs, in particular to bivalent bispecific antibodies and preparation methods thereof, encoding genes, host cells and compositions. The bivalent bispecific antibody comprises: a) a single-chain variable fragment scFv, a flexible peptide, a heavy chain IgG1 constant region CH1 and a partial hinge region sequence of an antibody that specifically binds to a first antigen, and b) that specifically binds a second antigen A single chain variable fragment scFv and light chain constant region CL of an antibody to an antigen, i.e. scFv1-CL or CL-scFv1; or comprising: c) light and heavy chains of an antibody that specifically binds to the first antigen; and d) specific The light and heavy chains of an antibody that binds the second antigen. The bivalent bispecific antibody of the present invention has high affinity to both the first antigen molecule and the second antigen molecule, the correct assembly rate of light and heavy chains is high, and the molecular size is moderate. |