<qa>  What is a Phase IV clinical trial designed to assess the safety of trastuzumaThis is a Phase IV, single-arm, multicenter, open-label clinical trial designed to assess the safety of trastuzumab emtansine in Indian patients with HER2-positive unresectable locally advanced breast cancer LABC or metastatic breast cancer mBC who have received prior treatment with trastuzumab and a taxane. 