OncoGenex Pharmaceuticals, Inc. announced that the European Patent Office (EPO) has granted European Patent Number EP1545561 entitled “Oligonucleotides for Treatment of Prostate and other Cancers.” The patent, licensed from The University of British Columbia, includes coverage for antisense and siRNA compositions that reduce the amount of active Heat Shock Protein 27 (Hsp27) in Hsp27 expressing cells. OGX-427 is encompassed by the granted claims.

“The issuance of this patent confirms our position as the leader in Hsp27 antisense therapeutics and provides us with a broad patent that applies well beyond particular cancers or particular compositions,” said Scott Cormack, president and CEO of OncoGenex. “This patent comes as we continue to evaluate additional phase II clinical trials and development plans for OGX-427.”

Patents covering OGX-427 and related products have already issued in the United States, Australia, New Zealand, India and South Africa. A number of patent applications are still pending in the US and in other jurisdictions.

OGX-427 is a second-generation antisense drug that is designed to reduce production of Hsp27, a cell-survival protein. Hsp27 is expressed in a variety of malignancies and can be induced by cell stress such as chemotherapy, radiation therapy, and hormone therapy. Hsp27 production has been shown to inhibit cell death in tumour cells through a variety of mechanisms.

OGX-427 is currently being developed in prostate and bladder cancer as follows: an investigator-sponsored phase I clinical trial evaluating OGX-427 administered directly into the bladder in patients with superficial bladder cancer, which was initiated in August 2009. Also an investigator-sponsored, randomized phase II 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 II clinical trial of OGX-427 in approximately 180 patients with metastatic bladder cancer, which is planned to initiate in the second half of 2011.

OncoGenex is a biopharmaceutical company committed to the development and commercialization of new cancer therapies that address treatment resistance in cancer patients.