ERBB2 and breast cancer: Moreover, its anti-tumor activity is comparable to or better than the combination of trastuzumab and pertuzumab (54).The results of a phase II study on the combination of KN026 and docetaxel for the treatment of HER2-positive breast cancer demonstrated good efficacy and a manageable safety profile in the first-line treatment of HER2-positive recurrent/metastatic breast cancer (55).