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FOR IMMEDIATE RELEASE

         BRISTOL-MYERS SQUIBB AND IMCLONE SYSTEMS ENTER INTO LANDMARK
          COMMERCIALIZATION AGREEMENT FOR IMPORTANT INVESTIGATIONAL
                             CANCER DRUG IMC-C225

           BRISTOL-MYERS SQUIBB TO ACQUIRE AN APPROXIMATE 20 PERCENT
                       EQUITY STAKE IN IMCLONE SYSTEMS

(PRINCETON, N.J., September 19, 2001) -- Bristol-Myers Squibb Company (NYSE:
BMY) announced today that it has reached an agreement with ImClone Systems
(NASDAQ: IMCL) to co-develop and co-promote IMC-C225 in the United States,
Canada and Japan. IMC-C225 is an investigational drug designed to target and
block the Epidermal Growth Factor Receptor (EGFR), which is overexpressed on
the surface of certain cancer cells. The companies believe this
investigational drug already has great potential in the treatment of several
cancers, including colon, head and neck, pancreatic and non-small cell lung
cancers. In February 2001, the U.S. Food and Drug Administration granted
ImClone Systems a Fast Track designation for IMC-C225 in the treatment of
refractory colon cancer.

The transaction between Bristol-Myers Squibb and ImClone Systems comprises a
commercial agreement for the co-development and co-promotion of IMC-C225, as
well as the acquisition of an equity stake in ImClone Systems. Under the terms
of the commercial agreement, Bristol-Myers Squibb will pay ImClone Systems a
total of $1 billion in three cash payments for the achievement of the
following milestones: one upon the signing of the agreement, one upon the
completion of the Biologics License Application (BLA) submission with the FDA,
and one upon the marketing approval of IMC-C225 by the FDA. In addition,
ImClone will receive a significant share of product revenues. The term of the
commercial agreement runs through at least 2018.

"As the worldwide leader in cancer drug development, Bristol-Myers Squibb is
constantly searching for breakthrough medicines to help patients in need and
ImClone Systems' IMC-C225 represents one of the most important advances in
cancer medicine since the introduction of TAXOL(R) (paclitaxel) in 1991," said
Peter R. Dolan, chairman and chief executive officer, Bristol-Myers Squibb.
"The partnership with ImClone Systems demonstrates our continued commitment to
achieve our strategies for growth; focuses our efforts on medicines with
blockbuster potential; broadens our growth opportunities through aggressive
external development; and is a significant step towards becoming a leader in
biologics."

In addition to the commercial agreement, Bristol-Myers Squibb will acquire
approximately 14.4 million shares of ImClone Systems stock though a tender
offer made to ImClone Systems shareholders at a price of $70 per share.
Bristol-Myers Squibb estimates that the dilution from the transaction will be
between $.05 and $.07 in 2002, and $.05 and $.07 in 2003. Thereafter, the
strategic agreement that extends at least through 2018 will be accretive and
incremental to the revenue and EPS growth of the Company. This purchase
indicates Bristol-Myers Squibb's long-term interest in the ImClone's potential
for growth in not only oncology drug development, but also in its
biotherapeutic capability, which is highly complementary to Bristol-Myers
Squibb's leadership in core therapeutic areas such as oncology. This
collaboration is the latest in a series of strategic moves to further
strengthen Bristol-Myers Squibb's medicines business, which has been the focus
of the company's Strategy for Growth to double sales, earnings and earnings
per share





between year-end 2000 and 2005. The acquisition is subject to clearance under
the Hart-Scott-Rodino Antitrust Improvements Act as well as other customary
conditions.

"Our partnership with Bristol-Myers Squibb is a landmark agreement within the
biopharmaceutical industry," stated Samuel D. Waksal, Ph.D., president and
chief executive officer of ImClone Systems Incorporated. "This agreement pairs
the pharmaceutical industry's premier oncology franchise with the leading
biotechnology company in the field of oncology which has developed a rich,
late-stage pipeline of biologic-based therapeutics. We believe that the
strength and vision of this agreement will provide a powerful added value for
our shareholders, as well as patients with cancer who may benefit from
treatment with IMC-C225."

ImClone Systems is studying IMC-C225 in a series of Phase II and Phase III
clinical trials. The company is conducting Phase II clinical studies of
IMC-C225 in combination with standard therapies in patients with various
stages of colorectal cancer, pancreatic cancer, head and neck cancer, and
non-small cell lung cancer. In addition to the Phase II studies, the company
is conducting a Phase III clinical trial combining IMC-C225 with chemotherapy
and another study combining IMC-C225 with radiotherapy as first line
treatments for head and neck cancer.

A leader in oncology for the past 40 years, Bristol-Myers Squibb continues to
demonstrate its ongoing commitment to the field of fighting cancer. In
addition to currently marketed medicines such as TAXOL, the Company has a deep
and diverse portfolio of investigational compounds representing novel
cytotoxic therapies and a wide array of new approaches to cancer therapy,
including promising new drug candidates such as novel taxanes, epothilones,
ras oncogene pathway, and matrix metalloproteinase inhibitors that block
growth of tumor blood vessels.

Bristol-Myers Squibb is an $18 billion pharmaceutical and related health care
products company whose mission is to extend and enhance human life.

Bristol-Myers Squibb will conduct an analyst conference call on Wednesday,
September 19 at 1:00 P.M. (ET) to discuss the transaction. The call-in number
is 913-981-5581. Investors may listen to the call by linking to the Webcast at
www.bms.com/ir. A replay of the call will be available through the close of
business, Wednesday, October 3, by calling 402-280-9013.


FOR BRISTOL-MYERS SQUIBB
Certain statements made in this press release, including the possible success
of the company's business and its technology goals, are forward-looking and
are made pursuant to the safe harbor provisions of the Securities Litigation
Reform Act of 1995. Such statements involve risks and uncertainties that may
cause the company's actual results or outcomes to be materially different from
those anticipated and discussed in this press release. Factors that may cause
such a difference include, but are not limited to, those risks and
uncertainties associated with the regulatory approval of the company's
proprietary drugs, and other risks included in the company's Annual Report on
Form 10-K and in the company's other filings with the Securities and Exchange
Commission during the past 12 month. We undertake no obligation to publicly
update any forward-looking statement, whether as a result of new information,
future events or otherwise.


This release does not constitute an offer to purchase, a solicitation of an
offer to purchase, or a solicitation of consents with respect to any
securities. Any such offer or solicitation will be made only by means of the
Offer to Purchase under the rules and regulations of the Securities and
Exchange Commission.

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