Definition

A human, Fabs-in-tandem immunoglobulin (FIT-Ig)-based, tetravalent, bispecific antibody targeting both the epidermal growth factor receptor EGFR and the hepatocyte growth factor receptor (HGFR;; cMet; c-Met), with potential antineoplastic activity. Upon administration, bafisontamab simultaneously targets and binds to wild-type or certain mutant forms of both EGFR and c-Met expressed on cancer cells, thereby preventing receptor phosphorylation. This prevents the activation of both EGFR- and c-Met-mediated signaling pathways and results in the inhibition of tumor cell proliferation. EGFR and c-Met, both upregulated or mutated in a variety of tumor cell types, play key roles in tumor cell proliferation. In bafisontamab, the two antigen-binding fragments (Fabs) are fused directly in a crisscross orientation resulting in four active and independent antigen binding sites.