OncoGenex Announces Data Highlighting OGX-427 at American Association of Cancer Research (AACR) 102nd Annual Meeting 2011

BOTHELL, Wash. and VANCOUVER, British Columbia, April 4, 2011 /PRNewswire/ -- OncoGenex Pharmaceuticals, Inc. (NASDAQ: OGXI) announced today that preclinical data utilizing their pipeline compound OGX-427 was presented at the AACR 102nd Annual Meeting 2011. The study demonstrated the ability of OGX-427 to inhibit Heat Shock Protein 27 (Hsp27), a cell-survival protein believed to play an important role in the proliferation of castrate resistant prostate cancer (CRPC) and resistance to standard therapies.

Hsp27, expressed in prostate cancer and a variety of other malignancies, can be induced by cell stress such as chemotherapy, radiation therapy, and hormone therapy. Molecular chaperones that are heat shock proteins such as Hsp27 act to repair the damage of misfolding of cell structures that can occur when a cell is stressed, thereby enhancing the ability of cancer cells to survive.

The goal of this study was to test the ability of OGX-427, a second-generation antisense therapy, and other mechanisms (siRNA and proteasome inhibition MG132) in silencing the effects of Hsp27. The study showed that OGX-427 inhibits Hsp27 and therefore a cell survival process called autophagy, to increase intracellular unfolded protein burden and cause prostate cancer cell death.

"As cancers become resistant to standard therapies we need to identify new ways to continue to effectively treat them," says Dr. Martin Gleave, Director of The Vancouver Prostate Centre at The University of British Columbia and researcher on this study. "This study confirms the potential utility of inhibiting cell-survival proteins like Hsp27, and the potential for OGX-427 as a novel therapeutic strategy to target for anti-cancer therapies."

These pre-clinical data further support the current OGX-427 development plan in prostate and bladder cancers:

• An Investigator-sponsored Phase 1 clinical trial evaluating OGX-427 administered directly into the bladder in patients with superficial bladder cancer, which was initiated in August 2009.
• An investigator-sponsored, randomized Phase 2 clinical trial evaluating OGX-427 when administered as monotherapy to patients with castrate-resistant prostate cancer. This trial will enroll approximately 72 patients and was initiated in September 2010.
• A planned Phase 2 clinical trial of OGX-427 in approximately 180 patients with metastatic bladder cancer, which is planned to initiate in the second half of 2011.  

The abstract presented today, as well as information on OncoGenex' lead compound custirsen (OGX-011), can be found on the AACR meeting website at: http://www.aacr.org/.

Additional information about OGX-427 and OncoGenex can be found on the company's website www.oncogenex.com.

About OncoGenex Pharmaceuticals

OncoGenex is a biopharmaceutical company committed to the development and commercialization of new cancer therapies that address treatment resistance in cancer patients. OncoGenex has a diverse oncology pipeline, with each product candidate having a distinct mechanism of action and representing a unique opportunity for cancer drug development. OncoGenex and Teva Pharmaceutical Industries Ltd. (NASDAQ:TEVA) have entered a global collaboration and license agreement to develop and commercialize OncoGenex' lead drug candidate, custirsen. Custirsen is currently in Phase 3 clinical development as a treatment in men with metastatic castrate-resistant prostate cancer. The companies plan to begin Phase 3 development of custirsen in first-line treatment of advanced, unresectable non-small cell lung cancer in 2011. OGX-427 is in Phase 2 clinical development; SN2310 has completed a Phase 1 clinical trial; and CSP-9222 and OGX-225 are currently in pre-clinical development.

OncoGenex' Forward Looking Statements:

This press release contains forward-looking statements within the meaning of the "safe harbor" provisions of the Private Securities Litigation Reform Act of 1995, including, but not limited to, statements concerning our anticipated product development activities, the timing and costs of these activities and the potential benefits of our product candidates. All statements other than statements of historical fact are statements that could be deemed forward-looking statements. These statements are based on management's current expectations and beliefs and are subject to a number of risks, uncertainties and assumptions that could cause actual results to differ materially from those described in the forward-looking statements. Such forward-looking statements are subject to risks and uncertainties, including, among others, the risk that the Company is unable to complete its product development activities as and when planned, if at all, the risk that the Company will be unable to commercialize any product candidates in development and the other risk factors set forth in the Company's filings with the Securities and Exchange Commission, including the Company's Annual Report on Form 10-K for fiscal year 2010. The Company undertakes no obligation to update the forward-looking statements contained herein or to reflect events or circumstances occurring after the date hereof, other than as may be required by applicable law.

SOURCE OncoGenex Pharmaceuticals