Oncothyreon's PX-866 is effective in preclinical model of pulmonary fibrosis

SEATTLE, May 18 /PRNewswire-FirstCall/ - Oncothyreon Inc. (Nasdaq: ONTY) (TSX:
ONY) today announced the presentation of data demonstrating the effectiveness
of Oncothyreon's PX-866 in a preclinical model of pulmonary fibrosis. The data
were presented earlier today by William D. Hardie, M.D., Associate Professor,
Pulmonary Medicine, Children's Hospital Medical Center, Cincinnati, Ohio, at
the American Thoracic Society International Conference in San Diego,
California. PX-866 is a small molecule inhibitor of phosphotidylinositol-3
kinase ("PI-3 kinase"), a key point of control of cellular responses including
signaling of cell survival and growth, migration and metabolism.
"PI-3 kinase is part of a signaling pathway that is believed to play an
important role in a number of human diseases that cause fibrosis, or scarring,
of the lungs," said Dr. Hardie. "Our model in mice mimics these diseases by
activating this pathway in the lungs with a growth factor called transforming
growth factor alpha. PX-866 prevented both the deterioration in lung function
and the fibrosis normally seen in the model. These results suggest that
inhibition of the PI-3 kinase pathway might be beneficial in such human lung
diseases as idiopathic pulmonary fibrosis."
"Although our current development program for PX-866 is focused on cancer, we
are very interested in the role the PI-3 kinase pathway is thought to play in
non-malignant diseases, including autoimmune and cardiovascular diseases,"
said Robert L. Kirkman, M.D., President and CEO of Oncothyreon. "We are
pleased that Dr. Hardie plans further studies of PX-866 in pulmonary disease."
Oncothyreon is currently conducting a Phase 1 trial of PX-866 in patients with
advanced metastatic cancer. Preliminary data from this trial are expected to
be presented at the American Society of Clinical Oncology meeting later this
month in Orlando, Florida.

About PX-866

PX-866 is an inhibitor of the PI-3-kinase/PTEN/AKT pathway, an important
survival signaling pathway that is activated in many types of human cancer.
Aberrant activation and regulation of PI-3 kinase is implicated in a large
proportion of human cancers including breast, glioma, colon, ovarian, prostate
and melanoma, where it leads to increased proliferation and inhibition of
apoptosis (programmed cell death). PX-866 has been shown to induce prolonged
inhibition of tumor PI-3 kinase signaling following both oral and intravenous
administration. The compound has been shown to have anti-tumor activity both
as a single agent and in combination with other agents in a number of human
tumor models. Oncothyreon initiated a Phase 1 trial of PX-866 in patients with
advanced metastatic cancer in June 2008.

About Oncothyreon

Oncothyreon is a biotechnology company specializing in the development of
innovative therapeutic products for the treatment of cancer. Oncothyreon's
goal is to develop and commercialize novel synthetic vaccines and targeted
small molecules that have the potential to improve the lives and outcomes of
cancer patients. For more information, visit www.oncothyreon.com.

Forward-Looking Statements

In order to provide Oncothyreon's investors with an understanding of its
current intentions and future prospects, this release contains statements that
are forward-looking, including statements related to future preclinical and
clinical development plans for PX PX-866. These forward-looking statements
represent Oncothyreon's intentions, plans, expectations and beliefs and are
based on its management's experience and assessment of historical and future
trends and the application of key assumptions relating to future events and
circumstances.
Forward-looking statements involve risks and uncertainties, including risks
and uncertainties related to Oncothyreon's business and the general economic
environment. Many of these risks and uncertainties are beyond Oncothyreon's
control. These risks, uncertainties and other factors could cause our actual
results to differ materially from those projected in forward-looking
statements. Risks, uncertainties, and assumptions include those predicting the
timing, duration and results of clinical trials, the timing and results of
regulatory reviews, the safety and efficacy of PX-866, and the indications for
which PX-866 might be developed. There can be no guarantee that the results of
preclinical studies will be predictive of either safety or efficacy in future
clinical trials. These and other risks and uncertainties are described in the
reports and other documents filed by Oncothyreon Inc. with the SEC and/or
Canadian regulatory authorities.
Although Oncothyreon believes that any 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 the risks
and uncertainties associated with Oncothyreon, you are encouraged to review
the official corporate documents filed with the securities regulators in the
United States on U.S. EDGAR and in Canada on SEDAR. Oncothyreon is under no
obligation to (and expressly disclaims any such obligation to) update or alter
its forward-looking statements whether as a result of new information, future
events, or otherwise.

SOURCE Oncothyreon Inc.

Investor and Media Relations Contact: Julie Rathbun, Rathbun Communications,
(206) 769-9219, ir@oncothyreon.com