ChemGenex Presents at the Molecular Medicine Tri-Conference in San Francisco

MELBOURNE, Australia, and MENLO PARK, California U.S.A.

April 22, 2005

Dennis Brown, Ph.D., president of ChemGenex Pharmaceuticals Limited (ASX: CXS), presented today at the Cambridge Healthtech Institute's Twelfth International Molecular Medicine Tri-Conference. The presentation on "Using Genomics to Accelerate Drug Development" described how ChemGenex uses genomic tools in pre-clinical and clinical development to accelerate development and increase chances of clinical success. Dr. Brown's presentation was part of a session on strategies to boost R&D productivity which included related presentations by Chiron, Genentech, Pfizer and Baxter Healthcare.

About ChemGenex Pharmaceuticals Limited (www.chemgenex.com)

ChemGenex Pharmaceuticals is a gene-based pharmaceutical company dedicated to improving the lives of patients by developing therapeutics in the areas of oncology, diabetes, obesity, and depression. ChemGenex currently has two compounds in Phase II clinical trials, Ceflatonin® for leukemia and Quinamed® for solid tumors, and has a significant portfolio of anti-cancer, diabetes, obesity and depression programs. The company's diabetes and obesity program is partnered with Merck KGaA and the depression program is partnered with Vernalis plc. ChemGenex currently trades on the Australian Stock Exchange under the symbol "CXS".

Gleevec® is a registered trade-mark of Novartis AG.

Contacts

Dr. Greg Collier (CEO and Managing Director)	Australia +61 3 5227 2752 USA +1 650 474 9800 ext 103
Dr. Dennis Brown (President and Director)	USA +1 650 474 9800 ext 108 Australia +61 3 5227 2703

Safe Harbor Statement

Certain statements made herein that use the words "estimate," 'project," "intend," "expect," "believe," and similar expressions are intended to identify forward-looking statements within the meaning of the US Private Securities Litigation Reform Act of 1995. These forward-looking statements involve known and unknown risks and uncertainties which could cause the actual results, performance or achievements of the company to be materially different from those which may be expressed or implied by such statements, including, among others, risks or uncertainties associated with the development of the company's technology, the ability to successfully market products in the clinical pipeline, the ability to advance promising therapeutics through clinical trials, the ability to establish our fully integrated technologies, the ability to enter into additional collaborations and strategic alliances and expand current collaborations and obtain milestone payments, the suitability of internally discovered genes for drug development , the ability of the company to meet its financial requirements, the ability of the company to protect its proprietary technology, potential limitations on the company's technology, the market for the company's products, government regulation in Australia and the United States, changes in tax and other laws, changes in competition and the loss of key personnel. These statements are based on our management's current expectations and are subject to a number of uncertainties that could change the results described in the forward-looking statements. Investors should be aware that there are no assurances that results will not differ from those projected.