SEATTLE, WA and BOULDER, CO, May 30, 2013 /PRNewswire/ - Oncothyreon Inc. (NASDAQ: ONTY) and Array BioPharma Inc. (NASDAQ: ARRY) today announced that they will collaborate to develop and commercialize ARRY-380, an orally active, reversible and selective small-molecule HER2 inhibitor. HER2, also known as ErbB2, is a receptor tyrosine kinase that is over-expressed in breast cancer and other cancers such as gastric and ovarian cancer. Array previously completed a Phase 1 clinical trial of ARRY-380 in patients with heavily pre-treated metastatic breast cancer which demonstrated that the compound was well tolerated and had anti-tumor activity. Oncothyreon has agreed to pay Array an upfront fee of $10 million upon initiation of the collaboration. Under the agreement, Oncothyreon will fund and conduct the clinical development of ARRY-380 through a defined set of combination proof-of-concept trials in patients with metastatic breast cancer, including patients with brain metastases. ARRY-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. This provides a strong rationale to explore whether ARRY-380 can provide benefit to patients with brain metastases, which occur in approximately one-third of women with metastatic HER2+ breast cancer. Oncothyreon and Array intend to jointly conduct Phase 3 development supported by the proof-of-concept studies, with each party retaining the right to opt out of further development and commercialization in exchange for a significant royalty. Array is responsible for worldwide commercialization of the product. Oncothyreon has a co-promotion right in the U.S., and the two companies will share the cost of U.S. commercialization, including any profit, equally. Outside of the U.S., Oncothyreon will receive a double-digit royalty on net sales intended to approximate a fifty percent profit share, and the two companies will share equally the proceeds from any sublicense of marketing rights.