CASC Cascadian Therapeutics, Inc. (delisted)

Oncothyreon Inc. (Nasdaq:ONTY), a clinical-stage biopharmaceutical company dedicated to the development of oncology products that can improve the lives and outcomes of patients, today announced that data from the company’s ongoing trials of ONT-380, an orally active, reversible and selective small-molecule HER2 inhibitor being developed for the treatment of  metastatic breast cancer, will be presented at the upcoming San Antonio Breast Cancer Symposium (SABCS) being held December 8-12, 2015 in San Antonio, TX.

“We are looking forward to presenting additional and updated clinical trial data on ONT-380 for the treatment of patients with HER2-positive breast cancer, including an analysis of patients that suffer from central nervous system (CNS) metastases, at SABCS,” said Robert L. Kirkman, M.D., President and CEO of Oncothyreon. “CNS metastases impact up to 50 percent of women with HER2-positive metastatic breast cancer and represent a major unmet medical need. ONT-380 is an exciting molecule that has the potential to provide a much needed treatment option for this patient population.”

The SABCS presentation details are as follows:

A phase 1b study of ONT 380, an oral HER2-specific inhibitor, combined with ado trastuzumab emtansine (T DM1), in HER2+ metastatic breast cancer (MBC)

First Author: Cristiano Ferrario, Segal Cancer Centre, Jewish General Hospital, Montreal, QCDate/Time: Friday, December 11, 2015 at 7:30-9:00 a.m. CT Session: Poster Session 4: Treatment: HER2-Targeted TherapyAbstract P4-14-20

ONT-380 in the treatment of HER2+ breast cancer central nervous system (CNS) metastases (mets)

First Author: Rashmi Krishna Murthy, MD Anderson Cancer Center, Houston, TXDate/Time: Friday, December 11, 2015 at 7:30-9:00 a.m. CT Session: Poster Session 4: Treatment: HER2-Targeted TherapyAbstract P4-14-19

About Oncothyreon

Oncothyreon is a clinical-stage biopharmaceutical company specializing in the development of innovative therapeutic products for the treatment of cancer. Our goal is to discover, develop and commercialize novel compounds that have the potential to improve the lives and outcomes of cancer patients. Our most advanced product candidate is ONT-380, an orally active and selective small molecule HER2 inhibitor. We are developing preclinical product candidates in oncology and immune-oncology using our protocell technology. For more information, visit www.oncothyreon.com.

Forward-Looking Statements

In order to provide Oncothyreon's investors with an understanding of its current results and future prospects, this release contains statements that are forward-looking. Any statements contained in this press release that are not statements of historical fact may be deemed to be forward-looking statements. Words such as "believes," "anticipates," "plans," "expects," "will," "intends," "potential," "possible" and similar expressions are intended to identify forward-looking statements. These forward-looking statements include Oncothyreon's expectations regarding clinical development activities.

Forward-looking statements involve risks and uncertainties related to Oncothyreon's business and the general economic environment, many of which are beyond its control. These risks, uncertainties and other factors could cause Oncothyreon's actual results to differ materially from those projected in forward-looking statements, including those predicting the timing, duration and results of clinical trials, the timing and results of regulatory reviews, the safety and efficacy of our product candidates, and the indications for which our product candidates might be developed. There can be no guarantee that the results of preclinical studies or clinical trials will be predictive of either safety or efficacy in future clinical trials. Although Oncothyreon believes that the forward-looking statements contained herein are reasonable, it can give no assurance that its expectations are correct. All forward-looking statements are expressly qualified in their entirety by this cautionary statement. For a detailed description of Oncothyreon's risks and uncertainties, you are encouraged to review the documents filed with the securities regulators in the United States on EDGAR and in Canada on SEDAR. Oncothyreon does not undertake any obligation to publicly update its forward-looking statements based on events or circumstances after the date hereof.

CONTACT:

Investor Relations:
Julie Rathbun
Rathbun Communications
206-769-9219
ir@oncothyreon.com

Media Relations:
Kelly France, Ph.D.
BrewLife
415-946-1076
kfrance@brewlife.com