Another bispecific, humanized IgG1 antibody that is definitely under investigation is zenocutuzumab (MCLA-128), which functions through two impartial mechanisms of action: inhibition of HER2–HER3 signalling and elimination of tumour cells by means of ADCC. MCLA-128 functions via a ‘dock and block’ mechanism whereby one arm of the antibody binds HER2 https://www.directivepublications.org/journal-of-clinical-breast-cancer/