OncoGenex and Sarah Cannon Announce Completion of Patient Enrollment in the Spruce™ Clinical Trial Evaluating Apatorsen in Combination with Carboplatin and Pemetrexed in Patients with Advanced Non-Squamous Non-Small Cell Lung Cancer

BOTHELL, WA., & VANCOUVER, BC – February 24, 2015 — OncoGenex Pharmaceuticals, Inc. (NASDAQ: OGXI) and Sarah Cannon announced today that patient enrollment has been completed in the Spruce™ clinical trial, an investigator-sponsored, randomized, placebo-controlled Phase 2 trial evaluating apatorsen in combination with carboplatin and pemetrexed in patients with previously untreated, advanced, non-squamous, non-small cell lung cancer (NSCLC). Spruce is sponsored and led by Sarah Cannon Research Institute (SCRI), the research arm of Sarah Cannon, Hospital Corporation of America’s (HCA) global cancer enterprise, and is being conducted at 16 sites across the United States.

In the Spruce trial, approximately 155 patients were randomized to receive either apatorsen or placebo in combination with carboplatin and pemetrexed therapy. The primary objective of the trial is progression-free survival (PFS), with additional analyses to evaluate overall survival, tumor response rates, safety, tolerability and the effect of therapy on heat shock protein 27 (Hsp27) levels.

“Despite advances in targeted therapies to treat lung cancer, the majority of patients lack specific biomarkers and chemotherapy remains a mainstay of treatment for these patients,” stated David Spigel MD, Director of the Lung Cancer Research Program at Sarah Cannon Research Institute and trial study chair. “The Spruce trial will enable us to better understand the role of apatorsen in treating NSCLC and its potential to delay or prevent treatment resistance and improve survival outcomes for these patients who urgently need more effective treatment options.”

Spruce is one of two randomized Phase 2 trials of apatorsen in NSCLC. The Cedar™ clinical trial, an investigator-sponsored, randomized, open-label, Phase 2 trial evaluating apatorsen in patients with previously untreated, advanced, squamous cell lung cancer is currently enrolling. Cedar is being conducted and funded primarily by the UK National Cancer Research Network and the UK Experimental Cancer Medicine Network at approximately 20 centers in the United Kingdom. For more information on OncoGenex or the Spruce trial, please visit www.oncogenex.com or http://clinicaltrials.gov/show/NCT01829113 .

About Lung Cancer
Lung cancer is the most common cancer worldwide, with approximately 1.8 million new cases per year. It is the leading cause of cancer death among both men and women in the US, with approximately 160,000 Americans expected to have died from the disease in 2014. About 85 to 90 percent of all lung cancers are identified as NSCLC, and are often found to be metastatic, or advanced, at diagnosis. Non-squamous histology NSCLC includes adenocarcinoma and large cell carcinoma, and accounts for more than half of all diagnoses. Squamous histology NSCLC, which accounts for about 25 to 30 percent of all lung cancer cases, has been reported to be associated with lower survival rates than NSCLC classified as adenocarcinoma; limited treatment options for squamous cell carcinoma currently exist. Although specific targeted therapy has been identified for a minority of patients, chemotherapy remains the backbone of treatment for the majority of patients with lung cancer.

About Apatorsen and ORCA™
Apatorsen (OGX-427) is a once-weekly intravenous (IV) experimental drug that is designed to inhibit production of heat shock protein 27 (Hsp27) to disable cancer cells’ defenses and overcome treatment resistance. Hsp27 is an intracellular protein that protects cancer cells by helping them survive, leading to resistance and more aggressive cancer phenotypes. Both the potential single-agent activity and synergistic activity of apatorsen with cancer treatments may increase the overall benefit of existing therapies and augment the durability of treatment outcomes, which could lead to increased patient survival.

The ORCA (Ongoing Studies Evaluating Treatment Resistance in CAncer) program encompasses clinical trials of apatorsen. Phase 2 clinical trials are underway in bladder, lung, pancreatic and prostate cancers. For more information on apatorsen and ORCA, please visit www.OncoGenex.com or www.orcatrials.com.

About OncoGenex
OncoGenex is a biopharmaceutical company committed to the development and commercialization of new 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. Custirsen is currently in Phase 3 clinical development as a treatment in men with metastatic castrate-resistant prostate cancer and in patients with advanced, unresectable non-small cell lung cancer. Apatorsen is in Phase 2 clinical development and OGX-225 is currently in pre-clinical development. More information is available at http://www.OncoGenex.com and at the company’s Twitter account https://twitter.com/OncoGenex_IR.

About Sarah Cannon Research Institute
Sarah Cannon Research Institute (SCRI) is a global strategic research organization focusing on advancing therapies for patients. It is one of the world’s leading clinical research programs, conducting community-based clinical trials in oncology and cardiology through affiliations with a network of more than 1,000 physicians in the United States and United Kingdom. Additionally, SCRI offers management, regulatory, and other research support services for drug development and industry sponsors and strategic investigator sites.

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 completion and design, as well as 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 our product candidates will not demonstrate the hypothesized or expected benefits, 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 and the other risks 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 and Quarterly Reports on Form 10-Q. 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.

Spruce™, Cedar™ and ORCA™ are registered trademarks of OncoGenex Pharmaceuticals, Inc.