SCO CAPITAL PARTNERS LLC

July 3, 2007

Board of Directors

Bioenvision, Inc.

345 Park Avenue, 41^st Floor

New York, New York 10154

Bioenvision Board Members:

As we anticipated, Genzyme’s tender offer for Bioenvision has failed. Given Genzyme’s Schedule 13D of May 29, 2007 stated that it beneficially owned 24.3%, Bioenvision’s other shareholders have rejected Genzyme’s tender offer by a majority of greater than 74% to 2%.

The Market Has Spoken - Again: As reflected in the 74% to 2% rejection, the $5.60 price is an unacceptably low offer. Despite being characterized as an offer at a premium, the $5.60 per share price represents a mere 6% premium to the prior day’s closing, and discounts of approximately 8%, 16% and 44% to the stock price of 1, 2, and 3 years prior, respectively. Genzyme’s offer was made off an artificially low market price, negatively impacted by an ill-timed, dilutive financing at a price near the four-year low. Market comparables for this type of transaction would require a price premium of between 50% and 100%, and based upon a more stable share price, or an offer price in the range of $8 to $12 per share. An offer at that level is still substantially below the target price of $13 per share that the UBS Securities (Bioenvision’s own financial advisor) analyst had set for Bioenvision shares.

Bioenvision Board of Directors Needs To Act: Bioenvision’s board of directors should heed the message in the overwhelming failure of the tender offer, and work with Genzyme to terminate this ill-timed transaction, or to achieve a price level acceptable to the common shareholders. All board members, including the Perseus-Soros/Aisling employees and designees, have a duty to all common shareholders, and the message was clear – the $5.60 tender offer price is unacceptable.

Genzyme as Minority Shareholder: While we believe that Genzyme’s proposed maneuvering with respect to closing on a minority position is just another way of scaring shareholders into tendering at an unacceptably low price, we do not believe that having Genzyme as a minority shareholder could be any worse than the minority shareholders that they are replacing.

1285 AVENUE OF THE AMERICAS, 35TH FLOOR, NEW YORK, NEW YORK 10019

Telephone: 212-554-4158 Fax: 212-554-4058

We applaud Bioenvision’s common shareholders for flatly rejecting the inadequate $5.60 tender offer from Genzyme. We strongly recommend that Bioenvision’s board of directors act in accordance with Bioenvision shareholders’ desire to terminate the tender offer, or negotiate a price that is consistent with market comparables and fair to all shareholders involved.

Sincerely,

/s/ Steven H. Rouhandeh

Steven H. Rouhandeh

1285 AVENUE OF THE AMERICAS, 35TH FLOOR, NEW YORK, NEW YORK 10019

TELEPHONE: 212-554-4158 FAX: 212-554-4058

BIOENVISION INC SC 13D/A