Bioenvision Completes Acquisition of Pathagon, Inc; Pathagon Adds Two Proprietary, Marketed Technologies to Bioenvision Portfolio.

Business Editors

LONDON & NEW YORK--(BUSINESS WIRE)--Feb. 4, 2002

Bioenvision, Inc. (OTCBB: BIOV) today announced the closing of its acquisition of Pathagon, Inc., a privately held company focused on the development of novel anti-infective products and technologies.

With the acquisition, Bioenvision adds to its portfolio the rights to two FDA approved and marketed anti-infective technologies, OLIGON(TM) and methylene blue.

Dr. Chris Wood MD, Bioenvision's President & CEO, commented, "we are very excited about this acquisition. The addition of two marketed anti-infective technologies broadens the robust Bioenvision anti-cancer portfolio, which includes our UK approved product Modrenal (Trilostane). We will be actively seeking additional marketing partners for OLIGON and methylene blue in the US and Europe, and are currently ramping up our efforts to partner Clofarabine in Europe and Modrenal worldwide."

Pathagon's proprietary OLIGON technology is an advanced biomaterial that creates an electrochemical reaction between dissimilar metals, silver and platinum. This reaction actively releases silver ions into the immediate surrounding environment over extended periods of time, and has demonstrated broad-spectrum effectiveness against bacteria, fungi and antibiotic resistant microorganisms. Silver ions, the active agent in materials incorporating the OLIGON technology, have been used for decades as an anti-microbial agent. The anti-microbial technology has been approved by the FDA in the US, and is being sold in select indications by Edwards Life Sciences. Additional license agreements for the technology are anticipated.

Pathagon also holds the worldwide rights to the use of thiazine dyes such as methylene blue to inactivate pathogens in human blood products. Methylene blue has been used in Europe for years to inactivate pathogens in fresh frozen, or transfusion, plasma. Additionally, thiazine dye technology may have a role in cancer treatment, either alone or in combination with Bioenvision's anti-cancer drugs.

Bioenvision was founded in 1997 to develop and market compounds in the oncology and anti-infective markets. The Company has a broad pipeline of products for the treatment of cancer: including Clofarabine, in development with ILEX Oncology, one product on the market (Modrenal(R)), for which the company has obtained regulatory approval for marketing in the United Kingdom for the treatment of post-menopausal breast cancer, multiple products in clinical trials and a broad pipeline of products in pre-clinical development. These products, derived from a number of different development platforms, include: the first drug in a new class of agents for hormone sensitive cancers, a potent agent which is proving effective in clinical trials in the treatment of acute and chronic leukemia, gene therapy products in early stages of development, a number of which have proof of principal in man, and a platform of cytostatic drugs in early stage development. In addition, these platforms also have various non-oncology indications that Bioenvision is exploring. For more information on Bioenvision please visit its website at www.bioenvision.com.

Bioenvision Safeharbor Statement: Certain statements contained herein are "forward-looking" statements (as such term is defined in the Private Securities Litigation Reform Act of 1995). Because such statements include risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. 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 in technology and product development; failure to successfully complete clinical trials; failure to receive market clearance from regulatory agencies; dependence on third parties and partners; and those risks described in filings made by Bioenvision with the SEC. Bioenvision disclaims any obligation to update these forward-looking statements. Investors are urged to be cautious in assessing the impact of such "forward-looking" statements.