Adherex Further Strengthens Patent Protection for Novel Approach to Cancer Therapy.

RESEARCH TRIANGLE PARK, N.C. -- Adherex Technologies Inc. (TSX:AHX), a biopharmaceutical company with a broad portfolio of clinical oncology products under development, today announced that it has been issued U.S. Patent No. 6,780,845, entitled "Compounds and Methods for Cancer Therapy." The patent covers the use of the Company's proprietary cancer therapeutic agents to reduce tumor size and provides broader cancer specific disease protection for its cadherin portfolio. The compounds work by preventing proteins, known as classical cadherins, from properly acting as the "biological glues" that hold tumor cells together. Cancer cells die through a process known as apoptosis when cell-to-cell binding is inhibited.

"This patent is important to Adherex as it focuses specifically on the core mission of the Company in the treatment of cancer and furthers our robust intellectual property position around our novel cadherin-antagonist platform," said William P. Peters, MD, PhD, Chairman and CEO of Adherex. "The core focus of Adherex is to address unmet needs in the treatment of cancer, including the need for new therapeutics. We are developing unique drugs that target both the cancer cells directly and the cells of the blood vessels within tumors. This approach offers a revolutionary and, thus far, safe way to battle tumor growth and spread."

Cancerous tumors are solid masses of cells, growing out of control, which require nourishment via blood vessels. N-cadherin, one type of "biological glue," is found in the blood vessels of some tumors and on some of the tumor cells themselves. Adherex' lead cadherin antagonist, Exherin(TM), works by targeting N-cadherin, thereby inhibiting the binding together of the tumor blood vessel cells or the tumor cells themselves, and causing the blood vessels to leak or rupture or the cancer cells to die by apoptosis.In studies conducted to date, the Company has found that healthy blood vessels outside the tumors have not been demonstrably affected. The drug is currently in a Phase I trial in Canada and beginning another Phase I trial in the U.S. at the MD Anderson Cancer Center. The Company anticipates initiating three Phase Ib/II trials in the U.S. and Europe as early as the end of 2004.

About Adherex Technologies

Adherex Technologies Inc. is a biopharmaceutical company with a broad portfolio of clinical oncology products under development. Four products are in the clinical stage of development including Exherin(TM), Adherex' lead cadherin antagonist compound, and STS, a drug that protects against severe hearing loss that is often produced by platinum-based anticancer agents. Adherex' intellectual property includes broad, interlocking protection for cadherin-mediated adhesion and represents what the Company believes to be the world's broadest portfolio of vascular targeting and cell adhesion modulating agents. For more information, please visit Adherex' website at www.adherex.com.

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