The indications of trastuzumab are distinctive; for example, Ontruzant can be utilized as a monotherapy or can be combined with other drugs in CHM for the management and treatment of human epidermal growth factor receptor 2 (HER2)-positive metastatic cancer, whilst Ogivri is indicated for the management and treatment of EBC, MGC, and MBC [87]. Here, ERBB2 is linked to metastatic malignant neoplasm.