International Journal Of Cancer Publishes New Data On The Novel Mode Of Action Of Bioenvision's Modrenal.

Business Editors/Health & Medical Writers

NEW YORK--(BUSINESS WIRE)--Aug. 29, 2002

Bioenvision, Inc.

- Correction of previously released material reprinted in its

entirety with revision to journal citation -

- Study published provides further evidence of compound's

effectiveness as a second estrogen receptor blocker -

Bioenvision, Inc. (OTCBB:BIOV) today announced that new data on the novel mode of action of Modrenal(TM) has been published in the International Journal of Cancer (Puddlefoot J.R. et al Int. J. of Cancer 101; 17-22 2002).

Modrenal is approved for marketing in the UK for the treatment of advanced breast cancer in postmenopausal women.

The published results are the culmination of extensive work by Professor Gavin Vinson's team from the Division of Biomedical Sciences at Queen Mary and Westfield College, London. They show that Modrenal works on cancer cells in a previously unrecognized way that clearly distinguishes it from other breast cancer treatments. Until the publication of these data it was thought that Modrenal acted solely by inhibiting the synthesis of estrogen. However, it has long been recognized that this action alone was insufficient to fully explain the beneficial clinical results of Modrenal. The new results show that Modrenal, in addition to inhibiting production of estrogen, also has a novel second mode of action that could explain the drug's broad clinical activity.

Christopher B. Wood, M.D., President and CEO of Bioenvision, commented, "The new data further support previous results which have been published showing the benefits of Modrenal to patients that have relapsed following other hormonal treatments, such as tamoxifen. We are honored and pleased that International Journal of Cancer, one of the world's premier cancer journals, accepted the data for publication."

Currently available anti-estrogens, such as tamoxifen, are competitive inhibitors that bind to the ligand binding sites of estrogen receptors (ER). Modrenal does not bind to the receptors but inhibits the receptors from binding to estrogen response elements in DNA and stops estrogen- stimulated gene transcription. Thus, the drug works in the cancer cell at a site different than most other breast cancer drugs and could therefore potentially be used when the other agents have failed. Also, of particular interest is the way in which Modrenal acts on the "second" estrogen receptor, ER beta. Recently published data suggest that ER beta may play an important role in the development of hormone sensitive cancers, such as breast and prostate cancer, and this recently-described receptor has become a prime target for new forms of treatment. A part of Modrenal's action is directed specifically at ER beta.

Modrenal has been shown to give response rates in excess of 40% in patients with breast cancer who have become resistant to other forms of hormone therapy. The new data suggest that the clinical benefits of Modrenal may be attributed to the novel action on the estrogen receptors along with its well-documented suppression of steroidogenesis.

About Modrenal

The lead compound, marketed under the trade names Modrenal(TM) and Modrastane(TM), is already approved by United Kingdom regulatory authorities for the treatment of advanced post-menopausal breast cancer. Clinical trials have shown the compound is effective in breast cancer patients, particularly after treatments with hormonal therapy, for example with tamoxifen, are no longer effective. Physicians and doctors interested in learning more about Modrenal are invited to contact the company at the details listed below.

About Bioenvision

Bioenvision's (OTC Bulletin Board: BIOV - News) 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 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); and other products in clinical trials. Bioenvision is also developing anti-infective technologies, including the OLIGON technology, an advanced biomaterial that has been approved for certain indications by the FDA in the U.S., and is being sold by Edwards Lifesciences Corp. 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.