Onartuzumab (MetMAb) is a unique, humanized and affinity-matured monovalent (one-armed) monoclonal antibody against the MET receptor. Onartuzumab potently inhibits HGF binding and receptor phosphorylation and signaling. Onartuzumab has antibody-like pharmacokinetics and antitumor activity.In Vitro:Onartuzumab acts specifically by blocking HGF α-chain (but not β-chain) binding to MET.
Onartuzumab blocks HGF binding to human c-Met with an inhibitory concentration (IC)50 of 1.8 nM and inhibits the subsequent induction of c-Met auto-phosphorylation and cell proliferation in many cancer cell lines[2].In Vivo:Onartuzumab (30 mg/kg, IP, twice a week for 2 mouth) suppresses tumor growth.