ERBB2 and breast cancer: For example, pertuzumab, another HER2-targeted agent, enhanced progression-free survival (PFS) and overall survival (OS) in metastatic HER2+ BC patients when in combination with trastuzumab and docetaxel in CLEOPATRA (5), and trastuzumab emtansine (T-DM1), an antibody-drug conjugate of HER2, significantly improved OS in previously treated advanced BC patients in EMILIA (6).