BIHC is a Her2-CD3 bispecific antibody constructed from a single-domain antibody targeting Her2 and a single-chain variable fragment (Fv) targeting CD3 , formatted in an IgG-like structure. BIHC demonstrates effective antitumor activity in vivo , specifically binding to tumor cells expressing Her2 and efficiently eliminating Her2 -positive cancer cells by recruiting T cells, thus being used in the study of Her2-positive cancers.