Oncothyreon Announces First Patient Dosed in Randomized Phase 2 ONT-380 Combination Trial in Patients with HER2-Positive Breast Cancer

--Study to Evaluate ONT-380 in Combination with Herceptin and Xeloda--

--Study Will Enroll HER2-Positive Breast Cancer Patients With and Without Brain Metastases--

SEATTLE, Feb. 29, 2016 -- Oncothyreon Inc. (Nasdaq:ONTY), a clinical-stage biopharmaceutical company dedicated to the development of therapeutic products that can improve the lives and outcomes of patients with cancer, today announced dosing of the first patient in a randomized, placebo-controlled Phase 2 trial of ONT-380 in combination with Herceptin® (trastuzumab) and Xeloda® (capecitabine). ONT-380 is an oral, HER2-selective, central nervous system (CNS)-active tyrosine kinase inhibitor. The trial is enrolling heavily pretreated patients with advanced HER2-positive breast cancer with or without brain metastases.  

“There is a great need for effective, well-tolerated treatments for women with progressing metastatic HER2-positive breast cancer, especially those with metastases to the brain, which develops in up to half of these patients and who are frequently excluded from clinical trials. With no approved therapy for the treatment of brain metastases, options for this patient population are currently limited,” said Erika Hamilton, M.D., director, Breast and Gynecologic Cancer Research Program, Sarah Cannon Research Institute. “This trial includes specifically designed endpoints around HER2-positive CNS disease to further explore the activity of ONT-380 in combination with Herceptin and Xeloda on brain metastases and the potential to address this unmet medical need.”

“Based on data from our Phase 1b studies, which show that the combination of ONT-380 with other active treatments was well tolerated and resulted in objective responses and prolonged, stable disease, we believe that ONT-380 has the potential to be an important new treatment for HER2-positive breast cancer patients, especially for women with brain metastases,” said Christopher S. Henney, chairman and interim CEO of Oncothyreon. “We are excited to advance the development of ONT-380 in the third-line metastatic setting with the initiation of this Phase 2 trial. Additionally, we continue to evaluate opportunities for ONT-380 and to establish the most efficient regulatory path forward.” 

About the Study

The clinical trial is a Phase 2 randomized, double-blind, placebo-controlled study of ONT-380 in combination with Herceptin and Xeloda in patients with pretreated, unresectable locally advanced or metastatic HER2-positive breast cancer. (ClinicalTrials.gov Identifier: NCT02614794) The trial is expected to enroll approximately 180 patients in multiple centers located in the United States, Canada and Western Europe. Patients must have been previously treated with a taxane, Herceptin, Perjeta (pertuzumab) and Kadcyla (ado-trastuzumab emtansine or T-DM1). Patients with or without brain metastases are eligible, including patients with asymptomatic untreated brain metastases not needing immediate local therapy and patients with previously treated brain metastases.

The trial’s objectives are to assess the efficacy, safety and pharmacokinetics of ONT-380 in combination with Herceptin and Xeloda. The primary endpoint is progression free survival (PFS) based on assessment of both CNS and non-CNS disease. Additional endpoints include time to CNS progression, objective response rate and overall survival.

About ONT-380

ONT-380 is an oral, CNS-active, reversible and selective small molecule HER2 inhibitor being developed for the treatment of metastatic breast cancer. Unlike other approved and investigational treatments, ONT-380 selectively inhibits HER2 without significant inhibition of EGFR (also called HER1), resulting in highly potent inhibition of HER2 while potentially avoiding the side effects associated with dual inhibitors, including skin rash and gastrointestinal toxicities. In addition, ONT-380 has been shown to have durable, objective responses in HER2-positive patients with brain metastases. Brian metastases impact up to 50 percent of women with HER2-positive metastatic breast cancer and represent a major unmet medical need.

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, results of clinical trials and potential benefits of its product candidates.

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
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Media Relations:
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BrewLife
415-946-1076
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