ERBB2 and breast cancer: It is approved for unresectable locally advanced or metastatic TNBC with two or more prior therapies, at least one of which in the metastatic setting, as well as for unresectable locally advanced or metastatic HR-positive/HER2-negative breast cancer, after failure of an endocrine-based therapy and at least two prior chemotherapies (based on the phase III ASCENT and TROPiCS-02 trial, respectively) [19,20,21].