ImClone Settles Patent Lawsuit and Gains Rights to Additional Intellectual Property

Business Wire, Sept 10, 2007

NEW YORK -- ImClone Systems Incorporated (NASDAQ: IMCL) today announced that it has signed settlement and sublicensing agreements with the Massachusetts Institute of Technology (MIT) and Repligen Corporation to end litigation related to U.S. Patent No. 4,663,281, which is owned by MIT and exclusively licensed to Repligen. All terms of the agreements have been finalized and the parties will submit a stipulation of dismissal to the court. This settlement eliminates the need for the trial proceedings previously scheduled to begin today, as well as any further court proceedings or decisions relating to damages sought from ImClone by MIT and Repligen with respect to U.S. Patent No. 4,663,281.

Pursuant to the terms of the settlement, ImClone will pay a total of $65.0 million in cash for full and final settlement of the claims against ImClone in the matter, as well as for a royalty-free, irrevocable worldwide sublicense to technology patented under U.S. Patent No. 4,663,281. The $65.0 million lump-sum payment ImClone has made to Repligen represents the full amount ImClone will pay to settle its litigation with MIT and Repligen. Repligen is responsible for providing MIT with its portion of the settlement payment.

Importantly, pursuant to the terms of the settlement, Repligen also granted to ImClone a royalty-free, irrevocable worldwide sublicense for the future use of other patented technology, including U.S. Patent No. 5,665,578, which is owned by Abbott Laboratories, but to which Repligen has the power to sublicense under an agreement between Abbott Laboratories and Repligen. U.S. Patent No. 5,665,578 is the patent upon which Abbott Laboratories sued ImClone for patent infringement earlier this year.

ImClone's payment of $65.0 million to Repligen will be reflected in ImClone's third quarter 2007 financial results.

"ImClone is very pleased to have reached this settlement with Repligen and MIT," said John H. Johnson, Chief Executive Officer of ImClone. "We are happy to put this litigation behind us and move forward in our efforts to continue to grow worldwide sales of ERBITUX[R]."

About ERBITUX(R) (Cetuximab)

ERBITUX is a monoclonal antibody (IgG1 Mab) designed to inhibit the function of a molecular structure expressed on the surface of normal and tumor cells called the epidermal growth factor receptor (EGFR, HER1, c-ErbB-1). In vitro assays and in vivo animal studies have shown that binding of ERBITUX to the EGFR blocks phosphorylation and activation of receptor-associated kinases, resulting in inhibition of cell growth, induction of apoptosis, and decreased matrix metalloproteinase and vascular endothelial growth factor production. In vitro, ERBITUX can mediate antibody-dependent cellular cytotoxicity (ADCC) against certain human tumor types. While the mechanism of ERBITUX's anti-tumor effect(s) in vivo is unknown, all of these processes may contribute to the overall therapeutic effect of ERBITUX. EGFR is part of a signaling pathway that is linked to the growth and development of many human cancers, including those of the head and neck, colon and rectum.

ERBITUX (Cetuximab), in combination with radiation therapy, is indicated for the treatment of locally or regionally advanced squamous cell carcinoma of the head and neck. ERBITUX as a single agent is indicated for the treatment of patients with recurrent or metastatic squamous cell carcinoma of the head and neck for whom prior platinum-based therapy has failed.

ERBITUX is indicated for the treatment of EGFR-expressing, metastatic colorectal carcinoma (mCRC) in combination with irinotecan for patients who are refractory to irinotecan-based chemotherapy, and as a single agent for patients who are intolerant to irinotecan-based therapy. The effectiveness of ERBITUX for the treatment of EGFR-expressing mCRC cancer is based on objective response rates.

For full prescribing information, including boxed WARNINGS regarding infusion reactions and cardiopulmonary arrest, visit http://www.ERBITUX.com.

Important Safety Information

Grade 3/4 infusion reactions, rarely with fatal outcome (less than 1 in 1000), occurred in approximately 3% (46/1485) of patients receiving ERBITUX (Cetuximab) therapy. These reactions are characterized by rapid onset of airway obstruction (bronchospasm, stridor, hoarseness), urticaria, hypotension, loss of consciousness, and/or cardiac arrest. Severe infusion reactions require immediate and permanent discontinuation of ERBITUX therapy.

Most reactions (90%) were associated with the first infusion of ERBITUX despite the use of prophylactic antihistamines. Caution must be exercised with every ERBITUX infusion as there were patients who experienced their first severe infusion reaction during later infusions. A 1-hour observation period is recommended following the ERBITUX infusion. Longer observation periods may be required in patients who experience infusion reactions.

Cardiopulmonary arrest and/or sudden death occurred in 2% (4/208) of patients with squamous cell carcinoma of the head and neck treated with radiation therapy and ERBITUX as compared to none of 212 patients treated with radiation therapy alone. Fatal events occurred within 1 to 43 days after the last ERBITUX treatment. ERBITUX in combination with radiation therapy should be used with caution in patients with known coronary artery disease, congestive heart failure and arrhythmias. Close monitoring of serum electrolytes, including serum magnesium, potassium, and calcium during and after ERBITUX therapy is recommended.