ARX788 demonstrated superior efficacy compared to that of the FDA-and EMA-approved trastuzumab emtansine (T-DM1) in mice bearing HER-2 positive HCC1954 breast and NCI-N87 gastric cancer xenografts [116] and in HER-2-positive or low-expression-level HER-2 breast and gastric tumor cell- and patient-derived xenograft models [117,118]. This evidence concerns the gene ERBB2 and gastric neoplasm.