Clinicians Highlight Anti-Cancer Potential of Bioenvision's Clofarabine at European Medical Meetings.

NEW YORK -- Clofarabine, Bioenvision's anti-cancer treatment in development for leukemias and solid tumors, was featured prominently in presentations from leading international physicians both at this month's pediatric oncology conference, the Societe Internationale D'Oncologie Pediatrique (SIOP) meeting in Oslo and at the National Cancer Research Network (NCRN) in Birmingham, U.K. Clofarabine is currently under evaluation by the European Medicines Evaluation Agency (EMEA) for the treatment of relapsed or refractory acute leukaemia in children.

During a core SIOP presentation, Dr Pamela Kearns, Senior Lecturer in Pediatric Oncology, University of Bristol, UK, highlighted data from ongoing Phase II studies, supporting the activity of clofarabine in children with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) who are refractory or relapsed to prior regimens of treatment. Citing the latest US data from 84 pediatric patients - 49 with ALL and 35 with AML, Dr Kearns drew attention to overall responses of 31% and 26%, respectively.

Dr Kearns commented: "The encouraging results from successive research programs demonstrate the effectiveness of clofarabine in the treatment of advanced childhood leukemias. The response rates achieved utilizing clofarabine as a single agent in such heavily pre-treated patients are very promising. In addition, the increased survival time that we are observing is clearly impressive".

Further discussions of the potential future role of clofarabine in cancer treatment took place at several additional workshops and meetings during SIOP.

Separately, at the National Cancer Research Network (NCRN) AML Forum meeting at the University of Birmingham, on September 17th 2004, Professor Alan Burnett, Chairman of the UK National Cancer Research Institute Hematological Oncology Study Group, proposed that clofarabine could be utilized as a lead agent in AML-16, the next major national phase of research in AML, set to involve more than 100 hospitals throughout the UK. With reference to the Phase II investigator initiated research conducted this year, where 64% of adult patients taking clofarabine as a single agent demonstrated a complete response (CR) after just one course, Professor Burnett emphasized the importance of bringing forward new and innovative treatments, in a therapeutic area where physicians desperately need new treatment options.

Hugh Griffith, Chief Operating Officer of Bioenvision Limited, said: "As clofarabine's profile continues to strengthen, we are encouraged that experienced and knowledgeable oncology specialists choose to discuss clofarabine favorably at these important scientific meetings. We will continue to work closely with physicians from around the world to ensure that clofarabine continues to be extensively evaluated in all patient groups which stand to benefit."

Clofarabine was submitted to the FDA for approval in March 2004 and to the EMEA for approval in July 2004, in each case, for the treatment of refractory or relapsed acute leukaemia in children.

About clofarabine

Clofarabine is a next-generation purine nucleoside antimetabolite. Nucleoside analogues are antimetabolites that affect DNA synthesis. Clofarabine was rationally designed to combine many of the favorable properties of the two most commonly used nucleoside analogs, fludarabine and cladribine, but is reported to have greater potency at damaging the DNA of Leukemia cells than these other agents. (Blood, "Mitochondrial Toxicity of Deoxyadenoside Analogs", November 15, 2000, Volume 96, Number 10). Bioenvision is the exclusive worldwide developer of clofarabine, except for U.S. / Canadian cancer applications which Bioenvision sublicensed to ILEX Oncology, Inc. (Nasdaq: ILXO). Bioenvision originally obtained its clofarabine development and commercialization rights under patents held by Southern Research Institute. ILEX Products, Inc., a subsidiary of ILEX, sponsored the Pivotal Phase II trials of clofarabine and recently completed the New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA) for clofarabine for the treatment of refractory or relapsed acute leukemia in children. In February 2004, ILEX announced its agreement to merge with Genzyme Corporation, a global biotechnology company. The merger, subject to FTC approval and other customary closing conditions, is expected to close in 2004.

About Bioenvision

Bioenvision's primary focus is the development and distribution of compounds and technologies for the treatment of cancer. Bioenvision has a broad pipeline of products for the treatment of cancer, including: Clofarabine (in co-development with ILEX Oncology, Inc.), Modrenal(R) (for which Bioenvision has obtained regulatory approval for marketing in the United Kingdom for the treatment of post-menopausal breast cancer following relapse to initial hormone therapy), and other products in clinical trials. Bioenvision is also developing anti-infective technologies, including the OLIGON technology; an advanced biomaterial that has been incorporated into various FDA approved medical devices. For more information on Bioenvision please visit our Web site at www.bioenvision.com.

Certain statements contained herein are "forward-looking" statements (as such term is defined in the Private Securities Litigation Reform Act of 1995). Because these statements include risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. Specifically, factors that could cause actual results to differ materially from those expressed or implied by such forward-looking statements include, but are not limited to: risks associated with preclinical and clinical developments in the biopharmaceutical industry in general and in Bioenvision's compounds under development in particular; the potential failure of Bioenvision's compounds under development to prove safe and effective for treatment of disease; uncertainties inherent in the early stage of Bioenvision's compounds under development; failure to successfully implement or complete clinical trials; failure to receive marketing clearance from regulatory agencies for our compounds under development; acquisitions, divestitures, mergers, licenses or strategic initiatives that change Bioenvision's business, structure or projections; the development of competing products; uncertainties related to Bioenvision's dependence on third parties and partners; and those risks described in Bioenvision's filings with the SEC. Bioenvision disclaims any obligation to update these forward-looking statements.