SEATTLE, WA, May 24, 2011 /PRNewswire/ - Oncothyreon Inc. (Nasdaq: ONTY) today announced it has initiated the Phase 2 portion of its ongoing Phase 1/2 trial of PX-866 in combination with the chimeric monoclonal antibody cetuximab (Erbitux®) following successful completion of the Phase 1 dose escalation portion of the study. 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 portion of the trial was to determine the maximum tolerated or recommended daily dose of PX-866 to be given in combination with the standard dose of cetuximab administered weekly to patients with either progressive metastatic colorectal carcinoma (CRC) or progressive, recurrent or metastatic squamous cell carcinoma of the head and neck (SCCHN). The Phase 1 portion enrolled a total of 11 patients treated at two different dose levels of PX-866 in combination with the standard weekly dose of cetuximab. Preliminary results indicated PX-866 to be safe and well-tolerated in this trial. The recommended daily dose of PX-866 in combination with cetuximab was determined to be the same as the single agent daily maximum tolerated dose of 8 mg. Additional results from the Phase 1 portion of the trial will be submitted for presentation at an upcoming scientific meeting.
The Phase 2 portion is an open-label, randomized evaluation of the antitumor activity and safety of PX-866 administered at the recommended daily dose in combination with cetuximab, versus cetuximab alone, in two groups of patients not previously treated with cetuximab. Group 1 will enroll patients with metastatic CRC who have a history of progression or recurrence following prior treatment with irinotecan and oxaliplatin containing regimens or who are intolerant of irinotecan. Patients with CRC and Kras mutations are excluded from the trial. Group 2 will enroll patients with incurable progressive, recurrent or metastatic SCCHN. The two groups will be randomized and evaluated independently.
Up to 144 patients may be enrolled in the Phase 2 portion of the study, including 72 (36 per arm) in each group. The primary endpoint of the Phase 2 portion is objective response rate based on RECIST criteria. Secondary endpoints include progression free and overall survival, duration of response and disease control rate. Additional information on the trial is available at clinicaltrials.gov.
PX-866 is a pan inhibitor of the PI-3K/PTEN/AKT pathway, a critical cell signaling pathway that is activated in many types of human cancer. Aberrant activation and regulation of PI-3K 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 demonstrated that PX-866 was well tolerated using both an intermittent and continuous (daily) dosing schedule, and that 8 of 19 evaluable patients treated with continuous dosing achieved stable disease as their best response.
Oncothyreon is conducting a broad development program of PX-866 including clinical trials evaluating the compound as a single agent and in combination with other agents in multiple cancer types. Current trials include the Phase 1/2 trial of PX-866 in combination with cetuximab (Erbitux®) in patients with progressive CRC or progressive, recurrent or metastatic SCCHN described above and a Phase 1/2 trial of PX-866 in combination with the chemotherapeutic agent docetaxel in patients with advanced cancers for which docetaxel is considered standard of care. In addition, the National Institute of Canada Clinical Trials Group is conducting a Phase 2 trial of PX-866 in patients with relapsed glioblastoma and is expected to initiate a Phase 2 trial of PX-866 in patients with castration-resistant prostate cancer.
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.
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 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. 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.