Adherex Enters Into Agreement With International Childhood Liver Tumour Strategy Group (SIOPEL) For Conduct of Phase III Trial of STS

Research Triangle Park, NC, October 30, 2006 - - Adherex Technologies Inc. (AMEX:ADH, TSX:AHX), a biopharmaceutical company with a broad portfolio of oncology products under development, today announced that it has entered into an agreement with the International Childhood Liver Tumour Strategy Group (known as SIOPEL), a multi-disciplinary group of specialists under the umbrella of the International Society of Pediatric Oncology (SIOP), for the conduct of a Phase III trial of sodium thiosulfate (STS), a drug that Adherex is developing to reduce or prevent hearing loss in children associated with platinum-based chemotherapies. The trial is projected to begin in early 2007.

“While medicine has made great strides in treating childhood cancers, some chemotherapies still have unfortunate, and potentially preventable, side effects,” said Penelope R. Brock, MD, PhD, FRCPCH, Consultant in Paediatric Oncology, Great Ormond Street Hospital for Children in the United Kingdom, and International Chairman for the STS study. “Cisplatin, for instance, continues to be an important treatment option but can cause permanent hearing loss. Such hearing loss can be so severe that some children, particularly the very young, are delayed in acquiring basic language skills. Others, unless expertly managed long-term, experience significant social disabilities and behavioral dysfunctions. Drugs that protect against this hearing loss, without interfering with the effectiveness of the chemotherapy, could greatly improve the quality of these children’s lives.”

The randomized Phase III trial is expected to enroll approximately 100 children with hepatoblastoma (liver cancer) from participating centers in some 30 countries. Patients will either receive cisplatin, a platinum-based drug frequently used to treat hepatoblastoma, or cisplatin + STS. The study, which will be coordinated through the Children’s Cancer and Leukaemia Group (CCLG) in the UK, is intended to compare the level of hearing loss (ototoxicity) associated with cisplatin alone versus the combination of cisplatin + STS, as well as the safety, tolerability and anti-tumor activity in both arms of the study.

“Hearing loss associated with platinum-based chemotherapies continues to be a significant problem, especially for children. This agreement with SIOPEL is an important step forward in Adherex’s development strategy for STS, allowing the conduct of a prospective, randomized trial of STS as an otoprotectant in reducing such hearing loss,” said William P. Peters, MD, PhD, Chairman and CEO of Adherex. “Currently, there are no approved drugs for protecting against this type of hearing loss. Under the terms of the agreement, Adherex will provide drug and drug distribution; the trial will otherwise be fully conducted by SIOPEL.”

Adherex, which has licensed intellectual property rights from Oregon Health & Science University (OHSU) for the use of STS as a chemoprotectant, also continues to work with the U.S. Children’s Oncology Group to initiate a prospective, randomized clinical trial of STS in pediatric patients in the United States. Investigators at OHSU have previously conducted Phase I and Phase II studies with STS, which have shown that STS reduces hearing loss associated with platinum-based chemotherapy. In one study, for instance, the need for hearing aids to overcome high frequency hearing loss was reduced from about 50% to less than 5%. STS is currently approved for use in humans as part of a treatment for cyanide poisoning.

About Adherex Technologies
Adherex Technologies Inc. is a biopharmaceutical company dedicated to the discovery and development of novel cancer therapeutics. We aim to be a leader in developing innovative treatments that address important unmet medical needs in cancer. We currently have multiple products in the clinical stage of development, including ADH-1 (Exherin™), eniluracil and sodium thiosulfate (STS). ADH-1, our lead biotechnology compound, selectively targets N-cadherin, a protein present on certain tumor cells and established blood vessels that feed solid tumors. Eniluracil, an oral dihydropyrimidine dehydrogenase (DPD) inhibitor, was previously under development by GlaxoSmithKline for oncology indications. STS, a drug from our specialty pharmaceuticals pipeline, protects against the disabling hearing loss that can often result from treatment with platinum-based chemotherapy drugs. With a diversified portfolio of unique preclinical and clinical-stage cancer compounds and a management team with expertise in identifying, developing and commercializing novel cancer therapeutics, Adherex is emerging as a pioneering oncology company. For more information, please visit our website at www.adherex.com.


This press release contains forward-looking statements that involve significant risks and uncertainties. The actual results, performance or achievements of the Company might differ materially from the results, performance or achievements of the Company expressed or implied by such forward-looking statements. Such forward-looking statements include, without limitation, those regarding the development plans of the Company and the expected timing and results of such development. We can provide no assurance that such development will proceed as currently anticipated or that the expected timing or results of such development will be realized. We are subject to various risks, including the uncertainties of clinical trials, drug development and regulatory review, our need for additional capital to fund our operations, the early stage of our product candidates, our reliance on collaborative partners, our history of losses, and other risks inherent in the biopharmaceutical industry. For a more detailed discussion of related risk factors, please refer to our public filings available at www.sedar.com and www.sec.gov.

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Melissa Matson

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Adherex Technologies Inc.

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