An additional bispecific, humanized IgG1 antibody that may be below investigation is zenocutuzumab (MCLA-128), which acts via two independent mechanisms of motion: inhibition of HER2–HER3 signalling and elimination of tumour cells through ADCC. MCLA-128 capabilities by way of a ‘dock and block’ mechanism whereby 1 arm on the antibody binds https://www.directivepublications.org/journal-of-clinical-breast-cancer/