EXHIBIT 99.1 [GRAPHIC OMITTED] FOR IMMEDIATE RELEASE - --------------------- ANNOUNCEMENT PURSUANT TO NASDAQ MARKETPLACE RULE 4803(A) MELBOURNE, AUSTRALIA, AND MENLO PARK, CALIFORNIA, U.S.A. (FEBRUARY 26, 2007). ChemGenex Pharmaceuticals Limited (ASX: CXS, NASDAQ: CXSP), today announced that it had received a Nasdaq Staff Deficiency Letter concerning its non-compliance with Nasdaq's audit committee requirement for continued listing as set forth in Marketplace Rule 4350. This non-compliance resulted from the resignation, as previously announced, of Mr. Peter Bradfield and Dr. Denis Wade from the board of directors, reducing the independent members of the audit committee to one. Nasdaq has requested the Company provide a specific plan and timetable to achieve compliance with the Rule. The Company will respond as requested and fully expects to regain compliance as soon as reasonably possible. This announcement is being made in compliance with Nasdaq Marketplace Rule 4803(a), which requires prompt disclosure of receipt of a non-compliance letter. ABOUT CHEMGENEX PHARMACEUTICALS LIMITED (WWW.CHEMGENEX.COM) ChemGenex Pharmaceuticals is a pharmaceutical development company dedicated to improving the lives of patients by developing therapeutics in the areas of oncology, diabetes, obesity, and depression. ChemGenex harnesses the power of genomics for target discovery and validation, and in clinical trials to develop more individualized therapeutic outcomes. ChemGenex's lead compound, Ceflatonin(R), is currently in phase 2/3 clinical trials for chronic myeloid leukemia (CML) and Quinamed(R) is in phase 2 clinical development for prostate, breast and ovarian cancers. The company has a significant portfolio of anti-cancer, diabetes, obesity and depression programs, several of which have been partnered with international pharmaceutical companies. ChemGenex currently trades on the Australian Stock Exchange under the symbol "CXS" and on NASDAQ under the symbol "CXSP". 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 Announcement Pursuant to Nasdaq Marketplace Rule 4803(a) Page 2 of 2 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. ###