The other investigators and clinical sites to participate in the trial are Dr. Donald Richards at The US Oncology Network, Tyler, TX, and Dr. Monica Mita at the Cedars-Sinai Medical Center in Los Angeles, CA.Dr. Jakob Dupont, Chief Medical Officer of OncoMed, commented, "The Wnt pathway has been an area of interest for breast cancer researchers for many years, and it is exciting to bring this novel Wnt targeting antibody, vantictumab, to the clinic to learn more about the safety and potential efficacy of the drug candidate in combination with paclitaxel in patients with advanced HER2 negative breast cancer." Paul Hastings, Chairman and Chief Executive Officer of OncoMed, noted, "Initiation of the Phase 1b portion of the vantictumab clinical development program is an important milestone for OncoMed and for our partnership with Bayer. The clinical data from this and two other Phase 1b trials with vantictumab could potentially lead to an opt-in decision by Bayer to take vantictumab into later stage randomized clinical trials." About Vantictumab (OMP-18R5) Vantictumab is a first-in-class antibody that has shown broad anti-CSC and anti-tumor activity in patient-derived xenograft tumor models. Vantictumab inhibits a key signaling pathway in cancer, the Wnt pathway. Specifically, vantictumab selectively targets Frizzled receptors, which are activators of Wnt signaling. Although vantictumab was originally identified by binding to Frizzled7, the antibody selectively targets five different Frizzled receptors. Vantictumab is currently in Phase 1a. Data from this clinical trial were presented at the European Cancer Conference (ECC 2013) in September 2013 in Amsterdam, NL. Biomarker data for this Phase 1a trial were presented at the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics in Boston, MA, in October 2013. Vantictumab is now being tested in combination with standard-of care-chemotherapy in a Phase 1b clinical trial in advanced HER2 negative Breast Cancer (vantictumab + paclitaxel). Two additional Phase1b trials are planned to start in 2013 with vantictumab in combination with standard-of-care chemotherapy in two distinct solid tumor indications. Vantictumab is part of OncoMed's collaboration with Bayer Pharma AG.