Margetuximab is an ADCC‐enhanced IgG1 Fc‐engineered variant of the approved anti‐HER2 mAb trastuzumab in phase III for HER2‐expressing cancers.66, 93 Alteration of five amino acids (L235V, F243L, R292P, Y300L and P396L) enhanced binding to FcγRIIIa which also had the additional effect of decreasing binding to the inhibitory FcγRIIb, and thereby increased its A‐to‐I FcγR ratio. This was apparent when compared with unmodified trastuzumab the  margetuximab showed enhanced ADCC against HER2+ cells in vitro and demonstrated superior antitumor effects in an HER2‐expressing tumor model in mice.