A further bispecific, humanized IgG1 antibody that's under investigation is zenocutuzumab (MCLA-128), which functions through two independent mechanisms of motion: inhibition of HER2–HER3 signalling and elimination of tumour cells by using ADCC. MCLA-128 features via a ‘dock and block’ system whereby just one arm on the antibody binds HER2 domain https://www.directivepublications.org/journal-of-clinical-breast-cancer/