Data from a Phase 2 Study Presented at the 2012 ASCO Annual Meeting Continues to Show Early Activity of OGX-427 in Patients with

Data from a Phase 2 Study Presented at the 2012 ASCO Annual Meeting Continues to Show Early Activity of OGX-427 in Patients with Prostate Cancer

BOTHELL, Wash. and VANCOUVER, British Columbia, June 4, 2012 /CNW/ - OncoGenex Pharmaceuticals, Inc. (NASDAQ: OGXI) announced today data from a Phase 2 study of its investigational compound OGX-427 in chemotherapy-naive metastatic castration resistant prostate cancer (mCRPC) patients will be presented during an oral presentation at the 2012 American Society of Clinical Oncology (ASCO) annual meeting on Tuesday, June 5. Preliminary results show a higher number of patients taking OGX-427 plus prednisone without disease progression at 12 weeks and with declines in prostate-specific antigen (PSA), compared with those taking prednisone alone.

Sixty-four of 72 planned patients have been randomized to the study and data on 42 patients [22 who received OGX-427 plus prednisone and 20 who received prednisone alone] are now available at or beyond the 12 week assessment time point. Highlights are as follows:

    --  In the OGX-427 plus prednisone arm, 71% of patients were
        progression-free at 12 weeks, compared to 40% in the prednisone
        alone arm. The primary efficacy endpoint of this study is
        defined as the proportion of patients without disease
        progression at 12 weeks where disease progression is based on
        any of the following parameters: PSA levels, measurable
        disease, bone lesions, global deterioration or requiring
        palliative radiation therapy.
    --  Fifty percent of patients who received OGX-427 plus prednisone
        experienced a >50% decline in PSA, versus 20% of patients who
        received prednisone alone.
    --  Among the 21 patients with baseline measurable disease, 44% (4
        of 9) in the OGX-427 plus prednisone arm had a measureable
        disease response compared to 0% (0 of 12) in the prednisone
        alone arm. There was 1 complete response in the OGX-427 plus
        prednisone arm.
    --  Circulating tumor cell declines from greater than or equal to 5
        to <5 occurred in 55% of patients receiving OGX-427 plus
        prednisone compared to 41% of patients receiving prednisone
        alone.
    --  The authors concluded that OGX-427 appears to be
        well-tolerated. Adverse events (AEs) have been predominately
        grade 1-2 and related to infusion reactions. Three grade 4 AEs
        have been reported and include dizziness, pulmonary embolus and
        one case of hemolytic uremic syndrome.

"We are encouraged by these early data that further support the ability of 
OGX-427 to suppress androgen receptor activity and tumor cell survival," said 
Dr. Kim Chi, a medical oncologist at BC Cancer Agency, British Columbia, 
Canada, and the primary investigator on the study. "This is important for both 
the clinical development of OGX-427 and to also further our understanding of 
how new and emerging therapies may work alone or in combination to treat mCRPC 
and battle treatment resistance – a serious issue in this and other cancers."

OGX-427 is believed to work by inhibiting the production of Hsp27, a 
cell-survival protein expressed in many types of cancers including prostate, 
bladder, pancreas, breast and non-small cell lung cancer. Overexpression of 
Hsp27 is thought to be an important factor leading to the development of 
treatment resistance and is associated with negative clinical outcomes in 
patients with various tumor types.

Along with this study, OGX-427 is currently being evaluated in a Phase 1 trial 
in superficial or muscle-invasive bladder cancer and a large, randomized Phase 
2 trial in metastatic bladder cancer. Initiation of a Phase 2 study of OGX-427 
plus Zytiga® is planned for later this year.

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. Phase 3 
development of custirsen in treatment of advanced, unresectable non-small cell 
lung cancer is expected to be initiated in 2012. OGX-427 is in Phase 2 
clinical development; OGX-225 is currently in pre-clinical development. More 
information is available at www.OncoGenex.com.

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, such as expected clinical trial initiation and 
completion and statements regarding the potential benefits and potential 
development 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 
final trial results will not demonstrate the same or any potential benefit as 
observed in preliminary trial results, the risk that subsequent studies may 
not confirm earlier trial results, the risk of delays in our expected clinical 
trials, the risk that new developments in the rapidly evolving cancer therapy 
landscape require changes in our clinical trial plans or limit the potential 
benefits of our product, the risk that our cash resources are insufficient to 
fund our planned activities for the time period expected and the other factors 
described in our risk factors set forth in our filings with the Securities and 
Exchange Commission from time to time, including the Company's Annual Report 
on Form 10-K. 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.

Zytiga is a registered trademark of the Johnson & Johnson Corporation

SOURCE OncoGenex Pharmaceuticals, Inc.

Media Contact: Jaime Welch, jwelch@oncogenex.com, +1-604-630-5403; Investor Relations Contact: Susan Specht, sspecht@oncogenex.com, +1-425-686-1535

http://www.OncoGenex.com

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CO: OncoGenex Pharmaceuticals, Inc. ST: Washington NI: HEA SHOW

-0- Jun/04/2012 12:01 GMT