Adherex Signs Screening Agreement With National Cancer Institute.

Business Editors

OTTAWA--(BUSINESS WIRE)--May 13, 2003

Adherex Technologies Inc. (TSX:AHX), today announced that it has entered into a screening agreement with the National Cancer Institute ("NCI") of the United States. Under the agreement, the NCI will evaluate the anticancer effects and vascular targeting capabilities of select compounds from Adherex's broad library of proprietary cadherin antagonists. The NCI will assess the selected drug candidates in vitro as well as in preclinical animal models. The classes of agents to be included under the agreement include peptide cadherin antagonist compounds for N-cadherin, E-cadherin, desmogleins, VE-cadherin and OB-cadherin, as well as Adherex's third generation small molecule, non-peptide cadherin antagonists.

"This agreement is very important for Adherex," said William P. Peters, M.D., Ph.D., CEO and Vice Chairman of the Board of Adherex Technologies Inc. "It brings the enormous capabilities of the NCI to the evaluation of these agents and will significantly accelerate the timeframe for the potential development of these compounds into clinically useful agents. The NCI has extraordinary scientific capabilities and resources that will be used to evaluate the relative effectiveness and to help us understand the mechanisms of action of our drugs. We would not have had the resources to conduct these studies on our own."

Under the terms of the agreement, NCI will evaluate selected compounds using a battery of laboratory and animal tests designed to screen for effectiveness and, where appropriate, comprehensively evaluate the mechanisms of action. The NCI may use both in-house capabilities as well as independent contractors in academia and industry for the evaluations.

About Adherex Technologies Inc.

Adherex Technologies is an Ottawa-based cancer therapeutics company with a broad portfolio of products under development. Four products are in clinical trials during 2003 including Exherin(TM), Adherex's lead cadherin antagonist compound and STS, a drug that protects against severe hearing loss that is often produced by platinum-based anti-cancer agents. For more information, please visit Adherex's Web site at www.adherex.com.

This news release shall not constitute an offer to sell or the solicitation of an offer to buy nor shall there be any sale of these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.

Certain information contained in this news release is forward-looking and is subject to unknown risks and uncertainties. The actual results, performance or achievements of the company may differ materially from the results, performance or achievements of the company expressed or implied by such forward looking statements.