Cyclacel In-Licenses Novel Anticancer Drug From Lorus Therapeutics

CYC381 preclinical programme has promising antitumour activity & novel cell cycle mechanism suited for biomaker clinical trials

Dundee, UK and Toronto, Canada, 24 September 2003 - imited, the UK-based biopharmaceutical company, and Lorus Therapeutics, Inc., a Canadian biotechnology company, announced today an agreement licensing to Cyclacel exclusive worldwide rights to a Lorus small molecule anticancer drug code-named CYC381 (also known as NC381) and related analogues. CYC381 is an orally available analogue of clotrimazole currently in preclinical development. It is a novel agent that has demonstrated potent antitumour activity in vivo against several human tumour xenografts. CYC381 appears to work by a cell cycle-related mechanism arresting cancer cells in the G1 phase of the cell cycle.

Lorus licensed rights to CYC381 and its analogues from Harvard Medical School. Harvard investigators identified compounds with potential anticancer activity based on clinical observations of the effects of clotrimazole, a commonly used antifungal drug, on cancer cells. Lorus’ research programme involved extensive evaluation of the clotrimazole analogue series in preclinical models resulted in the selection of CYC381 as the lead candidate. A joint effort by Lorus and the US National Cancer Institute succeeded in developing alternative formulations. As CYC381 is a racemic compound, Cyclacel plans to identify and take into clinical development a single enantiomer if test results continue to be supportive. CYC381’s anticancer effects are presumed to result from its inhibition of the initiation of translation (protein synthesis) particularly of cyclins A, E and D1.

This property makes CYC381 ideally suited for clinical trials aided by Cyclacel’s biomarker technology that is presently used in clinical trials of Cyclacel’s own drug candidates, such as CYC202. Cyclacel’s biomarker technology involves analysis of gene expression and proteins in the blood and tissues of patients receiving an anticancer drug that may correlate to the clinical benefit conferred on the patient by the drug.

Under the terms of the agreement Lorus will receive an upfront fee, milestones and royalties on product sales.

“We are pleased to enter into this partnership with Cyclacel”, said Dr Jim Wright, CEO of Lorus. “Lorus has built value into NC381 by identifying the promise of this new class of compounds acting on the cell cycle. At this time, Lorus is focusing its efforts on its clinical products Virulizin®, GTI-2040 and GTI-2501 and has been looking for a partner who could provide world class cell cycle biology and a proven track record of advancing novel compounds into the clinic. Cyclacel and its science team, led by Professor David Lane, is an excellent match with these criteria.”

Dr Bob Jackson, Cyclacel’s Executive Director of Research and Development, said, “CYC381, a racemic mixture of two optical isomers, is profoundly active in a range of tumour models through its inhibition of translation of key cell cycle regulating proteins. We have identified a path to development based on selection of the optimum isomer and development of a biomarker toolkit to support the clinical evaluation when formal preclinical tests are completed.”

Spiro Rombotis, CEO of Cyclacel said, “In-licensing CYC381 suggests that Cyclacel’s cell cycle scientific and pharmaceutical competences continue to be recognised by corporate partners such as Lorus. We systematically evaluate large numbers of in-licensing candidates with the objective of filling emerging gaps in our pipeline. We were impressed by the promise of CYC381 and are keen to use our suite of technologies to advance it into clinical development.”

About Cyclacel
Cyclacel is a biopharmaceutical company that designs and develops small molecule drugs that act on cell cycle regulators to stop uncontrolled cell division in cancer and other diseases involving abnormal cell proliferation. Cyclacel discovery integrates cell cycle biology expertise with a library of gene-based targets, RNAi functional genomics, chemogenomics and clinical biomarker technologies to rapidly deliver new drugs. The Company has six research and development programs underway. Most advanced is CYC202, a Cyclin Dependent Kinase (CDK) inhibitor, in Phase II trials for breast and lung cancer. It is also being explored for use in glomerulonephritis, an inflammatory disease associated with kidney cell proliferation. CYC381, a clotrimazole analogue acting on the cancer cell cycle is in preclinical development. Cyclacel has entered into corporate alliances with AstraZeneca, CV Therapeutics and a top 5 pharmaceutical major all in the oncology field.

About Lorus
Lorus is a biopharmaceutical company focused on the research and development of cancer therapies. Lorus’ goal is to capitalize on its research, pre-clinical, clinical and regulatory expertise by developing new drug candidates that can be used, either alone, or in combination, to successfully manage cancer. Through its own discovery efforts and an active acquisition and in-licensing program, Lorus is building a portfolio of promising anti-cancer drugs. Late-stage clinical developments and marketing will be done in cooperation with strategic pharmaceutical partners. Founded in 1986, Lorus Therapeutics Inc. is a public company listed on the Toronto Stock Exchange under the symbol LOR, and on the OTC BB exchange under the symbol LORFF.

Except for historical information, this press release contains forward-looking statements, which reflect the Company’s current expectation regarding future events. These forward-looking statements involve risks and uncertainties, which may cause actual results to differ materially from those statements. Those risks and uncertainties include, but are not limited to, changing market conditions, the successful and timely completion of clinical studies, the establishment of corporate alliances, the impact of competitive products and pricing, new product development, uncertainties related to the regulatory approval process, and other risks detailed from time-to-time in the Company’s ongoing quarterly filings, annual information form, annual reports and 20-F filings.

Lorus Therapeutics Inc.’s press releases are available through the Company’s Internet site: www.lorusthera.com.