New Clofarabine Data Presented at European Haematology Association Meeting; Durable, High Response Rates Achieved with Clofarabine in Adult Acute Myeloid Leukaemia -AML-.

STOCKHOLM, Sweden -- Bioenvision (Nasdaq: BIVNE) announced that results from clinical trials of clofarabine in adult AML were presented at the 10th European Hematology Association (EHA) meeting in Stockholm, Sweden. In the National Cancer Research Institute, UK (NCRI) multi-center study of older patients with AML who were unsuitable for intensive chemotherapy, the overall response for clofarabine was 67%. Eleven (42%) patients in this trial had abnormal cytogenetics, and of these 5 (45%) achieved a complete response (CR) with clofarabine. For patients with "normal" cytogenetic profile, the CR was 73%. In addition, the median duration of remission in patients responding to clofarabine is currently 9.5+ months.

Professor Alan Burnett, chief investigator of the NCRI study, commented. "the prognosis for all the patients included in this study is poor but clofarabine has achieved an excellent and durable response, even in the high-risk population."

Clofarabine's potential as the next generation of leukemia treatment was a focal point during a symposium led by specialists from the internationally recognized MD Anderson Cancer Research Center (MDACC), Houston, Texas. Dr. Stefan Faderl, presented data from five investigator-sponsored studies of clofarabine in adult AML that were conducted at the MDACC. In one of these studies, Clofarabine as first line treatment in adult AML provided a CR of 52% (31/60) and an overall response of 60% 36/60). A new randomized Phase II study in first-line patients was conducted at MDACC and presented for the first time in Europe. This investigator-sponsored study supported by our co-development partner, Genzyme Corporation (Nasdaq: GENZ), compared clofarabine as a single agent versus clofarabine in combination with low-dose ara-C in patients greater than or equal to 60 years (median age 72 years) and showed that clofarabine as a single agent achieved a CR of 45% (5/11) and clofarabine in combination with low-dose ara-C achieved a CR of 60% (12/20).

About Clofarabine

Clofarabine is a next generation of the drug class, purine nucleoside analogs that inhibit DNA production necessary for cancer cell growth. Bioenvision and Genzyme are co-developing clofarabine. Bioenvision holds an exclusive worldwide license to clofarabine (outside Japan and Southeast Asia). Bioenvision granted an exclusive sublicense to Genzyme to develop and commercialize clofarabine for cancer indications in the United States and Canada. Bioenvision holds an exclusive license in the US and Canada to all non-cancer indications and an exclusive, irrevocable option to develop and market clofarabine for all human applications in Japan and Southeast Asia.

Bioenvision originally obtained clofarabine development and commercialization rights under patents held by Southern Research Institute.

Clofarabine has been granted orphan drug designation for the treatment of adult and pediatric ALL and AML in the U.S. and Europe. In the U.S., orphan drug status extends market exclusivity for seven years. The FDA also recently granted an additional six months market exclusivity to clofarabine under the Best Pharmaceuticals for Children Act. In Europe, the designation provides marketing exclusivity for 10 years.

About Bioenvision

Bioenvision's primary focus is the acquisition, 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 Genzyme Corporation), 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.