Trastuzumab Deruxtecan versus Trastuzumab Emtansine for Breast Cancer

Background:Trastuzumab emtansine is the current standard treatment for patients with human epidermal growth factor receptor 2(HER2)-positive metastatic breast cancer whose disease progresses after treatment with a combination of anti-HER2 antibodies and a taxane.Methods:We conducted a phase 3,multicenter,open-label,randomized trial to compare the efficacy and safety of trastuzumab deruxtecan(a HER2 antibody-drug conjugate)with those of trastuzumab emtansine in patients with HER2-positive metastatic breast cancer previously treated with trastuzumab and a taxane.The primary end point was progression-free survival(as determined by blinded independent central review);secondary end points included overall survival,objective response,and safety.