We thank the patients and their families, PARP inhibitor the study site coordinators and nurses, all of whom made this study possible. Raymond Mankoski, M.D., Ph.D., Gerald Cox, M.D., Ph.D., and Lisa Underhill, M.S. of Genzyme, a Sanofi company

reviewed and contributed to this manuscript. Laurie LaRusso, Chestnut Medical Communications, provided medical writing support, which was funded by Genzyme. The study was supported by research funding from Genzyme to E.L., N.W., M.D., G.M.P., E.A.A., H.R., and A.Z. Authorship contributions M.J.P. designed the study; E.L., N.W., M.D., G.M.P., E.A.A., H.R. and A.Z. recruited patients and conducted the study research; J.A. performed the statistical analyses; M.J.P., A.C.P., and BAY 80-6946 L.R. analyzed and interpreted the results and wrote the manuscript. All authors reviewed early and final drafts of the manuscript and were fully responsible for the content and

editorial decisions related to this manuscript. Role of the funding source This trial was funded by Genzyme, a Sanofi company. The Genzyme project team developed the design and set-up of the trial in collaboration with study investigators and regulatory authorities. Study data were monitored by clinical research associates contracted to Genzyme in each study region. Analyses were performed by the Genzyme Biomedical Data Science and Informatics division. All authors had access to the study data. An independent Data Monitoring Committee (DMC) provided additional oversight Glycogen branching enzyme of patient safety through periodic and ad-hoc reviews of study data, and review of information on patient discontinuations/withdrawals. Genzyme provided funding for medical writing services. The decision to submit the manuscript for publication was made jointly

by all authors. “
“Breast cancer is the most common cancer in women and the second most common cancer worldwide [1]. In the last decade, targeted therapy in breast cancer has become part of routine clinical protocols all over the world. Trastuzumab, a humanized monoclonal antibody that targets human epidermal growth factor receptor 2 (HER2), is routinely used to treat patients with breast carcinoma who overexpress HER2 [2] and [3]; when combined with chemotherapy in the metastatic setting, trastuzumab improves progression-free survival and overall survival by years [4]. Other HER2-targeting drugs (e.g., the kinase inhibitor lapatinib [5], the antibody pertuzumab [6], the antibody–drug conjugate ado-trastuzumab emtansine [T-DM1] [7]) have been approved for use in the treatment of HER2-positive metastatic breast cancer. At the same time, it has been shown that lapatinib (when added to paclitaxel) [8] and pertuzumab (as a single agent) [9] offer no clinical benefit to patients with HER2-negative metastatic disease.