The letter below is rather self-explanatory. Bristol ceo Jim Cornelius (pictured below left) isn’t pleased with Carl Icahn’s mysterious maneuvering to extract a higher price than $60 a share from the big drugmaker for ImClone Systems.

Jim reminds Carl (pictured below right) that the “preliminary proposal” from the mystery suitor requires due dilingence, unlike the Bristol offer. And he reasserts Bristol’s claims to long-term US marketing rights for ImClone’s cash cow, the Erbitux cancer treatment and its follow-up compound. Remember, Bristol already owns 16 percent of ImClone. Perhaps this dance is a prelude to something larger involving yet another player?

Board of Directors
ImClone Systems Incorporated
180 Varick Street
New York, NY 10014
Care of Mr. Carl C. Icahn, Chairman of the Board

September 11, 2008

Dear Carl:

On July 31, Bristol-Myers made an all-cash offer to acquire ImClone (the “Company”) for $60.00 per share. We were disappointed to learn yesterday, nearly six weeks after we announced our offer, that ImClone’s special committee unilaterally rejected our offer without discussing its merits with us and our advisors.

We note that, as reported in ImClone’s press release yesterday, the preliminary proposal you received from an unnamed party is fully subject to due diligence. In contrast, we have made a formal written offer which has been approved by our Board of Directors, is not subject to due diligence and has been fully disclosed to ImClone’s stockholders.

As you know, Bristol-Myers holds the exclusive, long-term marketing rights in the United States to ERBITUX® and related compounds, including IMC-11F8. Bristol-Myers has no intention of agreeing to any modifications to these rights. ImClone also should understand that our offer is for the entire company, and any potential restructuring of the company could severely jeopardize ImClone’s value and deprive ImClone’s stockholders of the benefits of our offer.

Notwithstanding ImClone’s receipt of a highly conditional preliminary proposal from another party, we continue to look forward to engaging directly with ImClone and its financial and legal advisors to discuss the merits of our all-cash offer, which is not subject to due diligence or financing, to acquire the approximately 83% of ImClone that we do not already own.

Sincerely,

James M. Cornelius

Chairman and Chief Executive Officer

Copies to:
John H. Johnson
Chief Executive Officer
Andrew K.W. Powell
Senior Vice President and General Counsel