New Evoltra(R) Data Shows Impressive Response and Survival Rates.

Investor Call/Webcast Scheduled for 7:15 PM Evoltra[R] Data Presented at the 48(th) Annual Meeting of the American Society of Hematology

ORLANDO, Fla. -- Bioenvision, Inc. (NasdaqGM:BIVN) today announced new efficacy, survival and safety data on Evoltra([R])from its pivotal Phase II study BIOV-121 at the 48th Annual Meeting of the American Society of Hematology (ASH) in Orlando, Florida. These detailed data demonstrate significantly higher response rates and improved survival compared to the current standard of care, especially in high risk sub groups.

These data were reported in several presentations given by Prof. Alan Burnett, M.D., Chairman of the U.K. National Cancer Research Institute (NCRI) Hematological Oncology Study Group and the Chief Investigator of study BIOV-121. These new data included:

-- The demographics of the study population, who were considered
   unsuitable for intensive chemotherapy, were: median age 71 years;
   29% had adverse cytogenetics (no patients had favorable
   cytogenetics); 24% secondary AML; 74% of patients had greater than
   or equal to 1 co-morbidities

-- The overall response rate achieved with clofarabine (30mg/m2) was
   substantially higher than expected at 48% for the full analysis set
   (FAS) and 55% for the per protocol set (PPS). The complete response
   rate (CR + CRi) was 44% for the FAS and 50% for the PPS.

-- Complete response rates for the poor prognosis groups were: adverse
   cytogenetics 47%; secondary AML 31%; patients greater than or equal
   to 70 years 49%.

-- A pooled analysis was performed on study BIOV-121 and the NCRI AML
   14 trial in the elderly AML population unsuitable for intensive
   chemotherapy. The median overall survival for all patients was 152
   days for clofarabine, 105 days for LDAC, and 69 days for HU.

   The overall survival at 12 months for the poor prognosis groups
   were:

   -- Adverse Cytogenetics - clofarabine 28% compared with 0% for LDAC
      and 5% for HU;

        -- Secondary AML - clofarabine 50% compared with 18% for LDAC
           and 0% for HU;

        -- Wheatley Poor Risk Index - clofarabine 36% compared with
           16% for LDAC and 4% for HU.

-- In the pooled analysis the early death rate (within 30 days) was
   21% for clofarabine and 26% for both LDAC and HU. Of the 14
   patients with early deaths on clofarabine, 3 had neutropenic
   sepsis, 3 had infection, 3 had infection and acute renal failure,
   2 had hemorrhage, and 1 died with disease progression.

-- The most frequent treatment-related adverse events were nausea,
   vomiting, diarrhoea, and constipation which occurred in 42 (64%),
   31 (47%), 26 (39%) and 10 (15%) patients respectively.
   Treatment-related thrombocytopenia, anemia and neutropenia occurred
   in 29 (44%), 18 (27%) and 19 (29%) patients respectively.

-- In study BIOV-121 the median time to ANC recovery to greater than
   1.0 x 10(9)/L and platelet recovery to greater than 100 x 10(9)/L
   was 24 and 38 days respectively.

"Clearly, clofarabine is active as a single agent in adult patients with acute myeloid leukemia and who are not candidates for intensive therapy, and has a favorable risk/benefit profile," said Professor Alan Burnett, M.D. "As with all active anticancer agents, the patients need to be carefully monitored, however clofarabine achieves a high response rate and improved survival in these elderly patients.

"These data from the pivotal study BIOV-121 and the pooled analysis from other studies will form the basis of Bioenvision's filing with the European Medicines Agency (EMeA) for the use of clofarabine in adult AML patients over 65 years and who are considered unsuitable for intensive therapy. The data from this press release and the presentations at ASH relating to BIOV-121 reflect important results from the full data set which will form the basis for the European filing.

Investor Conference Call and Meeting at ASH

In conjunction with the release of the data at ASH, Bioenvision will host an investor meeting, conference call and webcast on Monday, December 11, 2006 at 7:15 p.m. ET.

Conference Call Information:
Date: 12/11/06
Time: 7:15 p.m. ET
Toll free: 866-585-6398
International: 416-849-9626
Web cast: www.bioenvision.com

A replay of the call and web cast will be available for 14 days.
Replay number toll free: 866-245-6755
Replay number international: 416-915-1035
Replay passcode: 780114
Web cast replay: www.bioenvision.com

About Evoltra([R]) (clofarabine)

The European Marketing Authorization for Evoltra([R]) (clofarabine) is for "the treatment of acute lymphoblastic leukemia (ALL) in pediatric patients who have relapsed or are refractory to at least two prior regimens and where there is no other treatment option anticipated to result in a durable response. Safety and efficacy have been assessed in studies of patients less than or equal to 21 years old at initial diagnosis."

Clofarabine is in clinical development for the treatment of other hematological cancers and solid tumors. Bioenvision has conducted nonclinical studies of Evoltra([R]) for the treatment of psoriasis and is planning further worldwide development of Evoltra([R]) in autoimmune diseases.

Evoltra([R])(clofarabine) is a next generation purine nucleoside analog. Bioenvision holds an exclusive worldwide license (excluding U.S. and Canada) for the cancer applications of clofarabine and an exclusive worldwide license for all non-cancer indications. Bioenvision granted an exclusive sublicense to Genzyme Corporation to develop and commercialize clofarabine for certain cancer indications in the U.S. and Canada, which Genzyme markets under the name of Clolar([R]). 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 both ALL and AML in the U.S. and Europe. In Europe, the designation provides marketing exclusivity for 10 years following Marketing Authorization.

About Bioenvision

Bioenvision's primary focus is the acquisition, development, distribution and marketing of compounds and technologies for the treatment of cancer. Bioenvision has a broad pipeline of products for the treatment of cancer, including: Evoltra([R]), 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. Bioenvision is also developing anti-infective technologies, including the OLIGON([R]) technology; an advanced biomaterial that has been incorporated into various FDA approved medical devices and Suvus([R]), an antimicrobial agent currently in clinical development for refractory chronic hepatitis C infection. 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.