SAN ANTONIO (EGMN) - The novel HER2 antibody-drug conjugate trastuzumab-DM1 showed impressive efficacy and tolerability as single-agent therapy for extremely refractory metastatic breast cancer in a phase II study. At the San Antonio Breast Cancer Symposium, Dr. Ian Krop reported on 110 participants in the open-label multicenter study. All patients had HER2-positive metastatic breast cancer that had progressed despite previous treatment in all cases with an anthracycline, a taxane, capecitabine,...