Oncothyreon Initiates Phase 1/2 Trial of its PI-3 Kinase Inhibitor PX-866 in Combination with Docetaxel

SEATTLE, Nov. 3 /PRNewswire-FirstCall/ - Oncothyreon Inc. (Nasdaq: ONTY) today announced enrollment of the first patient in a Phase 1/2 trial of PX-866 in combination with the chemotherapeutic agent docetaxel. PX-866 is a small molecule compound designed to inhibit the activity of phosphatidylinositol-3-kinase (PI-3K), a component of an important cell survival signaling pathway.

The primary objective of the Phase 1 dose-escalation portion of the trial is to determine the maximum tolerated or recommended daily dose of PX-866 to be given in combination with the standard dose of docetaxel administered once every three weeks to patients with advanced cancers for which docetaxel is considered standard of care. The Phase 2 portion of the trial will consist of two independent arms examining PX-866 in combination with docetaxel in patients with specific tumor types.  One arm will include patients receiving second or third line treatment for non-small cell lung cancer, while the second arm will include patients receiving treatment for locally advanced, recurrent or metastatic squamous cell carcinoma of the head and neck. A potential third arm may be included to study an additional indication based on analyses of patient data from the Phase 1 portion of the trial.

The Phase 1/2 open-label trial is expected to enroll up to 117 patients if three separate indications are evaluated in Phase 2.  The primary endpoint of the Phase 1 portion of the trial is safety.  The primary endpoint of the Phase 2 portion is a combination of objective response rate and early progression rate. Secondary endpoints include duration of response, disease control rate and progression free survival.  Endpoints for the Phase 2 portion of the trial will be independently determined for each indication.

"We are excited to participate in this combination trial of PX-866 with docetaxel," said Dr. Antonio Jimeno, University of Colorado Cancer Center, Aurora, Colorado, and Principal Investigator of the trial. "We were encouraged to move forward with this indication by supportive preclinical data, and by the tolerability profile and disease stabilization in heavily pre-treated patients seen in the initial Phase 1 trial of PX-866." Other participating centers include The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins (Baltimore, MD) and Roswell Park Cancer Institute (Buffalo, NY).

"We are pleased to have initiated this first of four planned Phase 1/2 and Phase 2 trials of PX-866," said Robert L. Kirkman, M.D., President and CEO of Oncothyreon. "We are committed to a broad Phase 2 development program for PX-866, in combination with other agents, as a single agent, and in multiple tumor types, to maximize our opportunity to demonstrate the utility of this novel, irreversible PI-3K inhibitor."

About PX-866

PX-866 is an inhibitor of the PI-3-kinase/PTEN/AKT pathway, a critical cell 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, where it leads to increased proliferation and inhibition of apoptosis (programmed cell death). Results from a single-agent Phase 1 open-label, dose escalation study of PX-866 in patients with advanced metastatic cancer presented at the American Society of Clinical Oncology earlier this year demonstrated that PX-866 was well tolerated using both an intermittent and continuous (daily) dosing schedule. In the continuous dosing arm, 6 of 8 patients evaluable at the time of the presentation (or 75 percent) had stable disease as best response per RECIST criteria.  Additional data from the Phase 1 trial will be presented at the EORTC/NCI/AACR meeting in Berlin on November 18, 2010.

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 our product candidates. 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.

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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.