Exhibit 99.1
OncoGenex Pharmaceuticals, Inc. Closes $50 Million Public Offering
BOTHELL, WA, and VANCOUVER, October 22, 2010 — OncoGenex Pharmaceuticals, Inc. (NASDAQ: OGXI)
today announced that it has completed a public offering of 3,174,602 units at a price to the public
of $15.75 per unit for an aggregate offering amount of $50 million, as previously announced on
October 18, 2010. The net proceeds to OncoGenex, after underwriting discounts and commissions and
other offering expenses, from the sale of the units is approximately $46.7 million. The Company
intends to use the net proceeds from the offering primarily to advance its product pipeline,
including its lead program, custirsen, and OGX-427, which is currently in clinical development as a
treatment for prostate cancer and bladder cancer, as well as for general corporate purposes.
Stifel Nicolaus Weisel acted as sole book-running manager and Needham & Company, LLC, Rodman &
Renshaw, LLC and Wedbush PacGrow Life Sciences acted as co-managers.
The offering was made to purchasers outside of Canada pursuant to an effective shelf registration
statement that OncoGenex filed with the Securities and Exchange Commission, or the SEC, on June 26,
2009, as amended on July 13, 2009. A final prospectus supplement relating to the offering was
filed with the SEC on October 19, 2010. Copies of the prospectus supplement and the prospectus
relating to these securities may be obtained by contacting Stifel, Nicolaus & Company,
Incorporated, One Montgomery Street, Suite 3700, San Francisco, California 94104, Attention:
General Counsel, (415) 364-2500. Electronic copies of the prospectus supplement and accompanying
prospectus are also available on the website of the SEC at http://www.sec.gov.
This press release does not constitute an offer to sell or the solicitation of an offer to buy
shares of common stock and warrants of OncoGenex Pharmaceuticals, Inc., nor shall there be any sale
of these securities in any state or jurisdiction in which such an offer, solicitation or sale would
be unlawful prior to registration or qualification under the securities laws of any such state or
jurisdiction.
About OncoGenex
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 deep
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. have entered a global collaboration and