RESEARCH TRIANGLE PARK, N.C. — Oncology product developer, Adherex Technologies Inc. (AMEX:ADH) (TSX:AHX), says the U.S. Food and Drug Administration has cleared its Investigational New Drug (IND) application for eniluracil. The company in-licensed Eniluracil from GlaxoSmithKline in July 2005. This IND clearance enables Adherex to commence U.S.-based clinical trials of eniluracil.

“This regulatory clearance by the FDA was an important step in our efforts to rapidly develop eniluracil. In less than four months, we now have clinical quality drug and have submitted and received regulatory clearance to proceed with our initial clinical trials. We expect these trials to initiate very soon,” said William P. Peters, MD, PhD, MBA, Chairman and CEO.

“GSK extensively studied eniluracil, in some 1500 patients, so we already know a good deal about this drug. For instance, we know that the dose ranges we plan to use in our clinical studies were well tolerated. And, as we presented in our recent conference call, we now understand the reasons that GSK’s Phase III trials failed and how to correct those problems.”

Adherex’s development program for eniluracil includes preliminary studies designed to further define the optimal dose of eniluracil; the optimal dose ratio and schedule of eniluracil in combination with 5-FU and the anti-tumor activity of the proper combination of the two drugs. Two of these studies will be conducted in the U.S.:The first study will enroll approximately 20 patients with colorectal cancer who will undergo surgery to remove their tumors. These patients will receive an oral dose of eniluracil prior to their surgery. Samples of tumor and normal tissues will be evaluated for the duration of eniluracil’s effect on the enzymes involved in the activation and breakdown of 5-FU. This trial is expected to begin shortly, with data available in the first half of 2006.The second study will enroll approximately 20 patients. This Phase I trial is expected to initiate in early 2006 and be completed in six to eight months. Adherex expects that this trial will evolve into a Phase II trial in breast cancer patients, which should conclude in the first half of 2007.

In addition, Adherex plans to begin a Phase I/II trial in Asia in the second quarter of 2006 in patients with liver cancer. It is expected that a Phase III trial in liver cancer could begin by mid-2007.

Eniluracil is a drug designed to improve the effectiveness of 5-FU, one of the world’s most commonly used chemotherapies, by inhibiting its breakdown. Although 5-FU is a mainstay of contemporary cancer therapy, it has some therapeutic drawbacks, including that it must be given intravenously, it can cause severe and dose-limiting side effects, and it has variable blood and tissue levels which impact its anti-tumor activity and safety profile. In combination with eniluracil, 5-FU can become orally active, have fewer side effects, and more uniform and prolonged blood levels, thereby potentially improving its safety and anti-tumor effect.