SEATTLE, WA, Sept. 3, 2013 /PRNewswire/ - Oncothyreon Inc. (NASDAQ: ONTY) today announced the initiation of an investigator-sponsored trial of ONT-380 in combination with trastuzumab (Herceptin®) in patients with brain metastases from HER2+ breast cancer. The trial is being conducted under the sponsorship of the Dana-Farber Cancer Institute, Boston, Massachusetts. ONT-380 (also known as ARRY-380) is an orally active, reversible and selective small-molecule HER2 inhibitor being developed by Oncothyreon in collaboration with Array BioPharma Inc., Boulder, Colorado. The Phase 1 trial is a dose-escalation trial in up to 50 patients. The primary objectives are to determine the maximum-tolerated dose and recommended Phase 2 dose and schedule of ONT-380 in combination with trastuzumab in patients with HER2+ breast cancer and central nervous system (CNS) metastases. Secondary objectives include CNS objective response rate by both RECIST and volumetric criteria, progression-free survival and overall survival. The study will be conducted in two parallel arms with two dose regimens of ONT-380, either once-daily or twice-daily, in combination with standard dose trastuzumab. "ONT-380 has demonstrated superior activity, based on overall survival, compared to Tykerb ® (lapatinib) and to the investigational drug, neratinib, in an intracranial HER2+ breast cancer xenograft model," said Robert L. Kirkman, M.D., President and CEO of Oncothyreon. "This provides a strong rationale to explore whether ONT-380 can provide benefit to patients with brain metastases, and we are pleased that the Dana Farber Cancer Institute is undertaking this trial." "CNS metastases, which occur in one-third to one-half of women with metastatic HER2+ breast cancer, remain a significant clinical problem," said Nancy U. Lin, M.D., Principal Investigator of the Phase 1 trial and Clinical Director, Breast Oncology, Dana-Farber Cancer Institute. "There is an urgent need for new therapies to treat patients with brain metastases from breast cancer, and we are excited to begin this study of ONT-380". About ONT-380 ONT-380 is an orally active, reversible and selective HER2 inhibitor. In multiple preclinical tumor models, ONT-380 was well tolerated and demonstrated significant dose-related tumor growth inhibition that was superior to Herceptin and Tykerb. Additionally, in these models, ONT-380 demonstrated synergistic or additive tumor growth inhibition when dosed in combination with the standard-of-care therapeutics Herceptin or Taxotere® (docetaxel).