ImClone Systems Issues Statement Regarding Positive Opinion from CHMP for Use of ERBITUX(R) in Head and Neck Cancer.

NEW YORK -- ImClone Systems Incorporated (NASDAQ: IMCL) today issued the following statement regarding the announcement that Merck KGaA, Darmstadt, Germany, has received a positive opinion from the Committee for Medicinal Products for Human Use (CHMP), the scientific committee of the EMEA (European Medicines Agency), for its application to extend the use of ERBITUX(R) (Cetuximab), an IgG1 monoclonal antibody, to the treatment of squamous cell carcinoma of the head and neck (SCCHN):

"We are pleased that our partners, Merck KGaA, may soon be able to offer ERBITUX to head and neck cancer patients in the European Union. This is the first new modality of treatment for this disease state since chemoradiation began use over thirty years ago," stated Eric K. Rowinsky, M.D., Chief Medical Officer of ImClone Systems.

The CHMP opinion recommends marketing authorization by the European Commission for the use ERBITUX in combination with radiation in patients with locoregionally advanced SCCHN. The license application is based on the results from a randomized, international phase III trial (IMCL-9815), conducted by ImClone Systems and Merck KGaA, which examined the impact of combining ERBITUX with radiation on locoregional control and overall survival in 424 patients with locally or regionally advanced SCCHN.

About Head and Neck Cancer

In Europe alone, around 100,800 people are diagnosed with head and neck cancer and almost 40,000 die from the disease every year.(1) Head and neck cancer is the sixth most frequently occurring cancer worldwide.(2) Head and neck cancer includes cancers of the tongue, mouth, salivary glands, pharynx, larynx, sinus, and other sites located in the head and neck area. About 90 percent of head and neck cancers are of the squamous cell variety(3) and nearly all express epidermal growth factor receptor (EGFR), which is critical for tumor growth.(4)

About ERBITUX(R) (Cetuximab)

On February 12, 2004, the FDA approved ERBITUX for use in the United States in combination with irinotecan in the treatment of patients with EGFR-expressing, metastatic colorectal cancer who are refractory to irinotecan-based chemotherapy and for use as a single agent in the treatment of patients with EGFR-expressing, metastatic colorectal cancer who are intolerant to irinotecan-based chemotherapy. The effectiveness of ERBITUX for the treatment of colorectal cancer is based on objective response rates. Currently, no data are available that demonstrate an improvement in disease-related symptoms or increased survival with ERBITUX in metastatic colorectal cancer patients.

ERBITUX binds specifically to the epidermal growth factor receptor (EGFR, HER1, c-ErbB-1) on both normal and tumor cells, and competitively inhibits the binding of epidermal growth factor (EGF) and other ligands, such as transforming growth factor-alpha. The EGFR is constitutively expressed in many normal epithelial tissues, including the skin and hair follicle. Over-expression of EGFR is also detected in many human cancers including those of the colon and rectum.

Important Safety Information

Severe infusion reactions, rarely fatal and characterized by rapid onset of airway obstruction (bronchospasm, stridor, hoarseness), urticaria, and hypotension, have occurred in approximately 3% (20/774) of patients with the administration of ERBITUX. Most reactions (90%) were associated with the first infusion of ERBITUX despite the use of prophylactic antihistamines. Severe infusion reactions require immediate and permanent discontinuation of ERBITUX therapy. 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.

Severe cases of interstitial lung disease (ILD), which was fatal in one case, occurred in less than 0.5% of 774 patients receiving ERBITUX.

Dermatologic toxicities, including acneform rash (11% of 774 patients, grade 3/4), skin drying and fissuring, inflammatory or infectious sequelae (e.g., blepharitis, cheilitis, cellulitis, cyst) and paronychial inflammation (0.4% of 774 patients, grade 3) were reported. Sun exposure may exacerbate any skin reactions.

Hypomagnesemia has been reported with ERBITUX when administered as a single agent and in combination with multiple different chemotherapeutic regimens. The incidence of hypomagnesemia (both overall and severe (NCI CTC grades 3 & 4)) was increased in patients receiving ERBITUX alone or in combination with chemotherapy as compared to those receiving best supportive care or chemotherapy alone based on ongoing, controlled clinical trials in 244 patients. Approximately one-half of these patients receiving ERBITUX experienced hypomagnesemia and 10-15% experienced severe hypomagnesemia. Electrolyte repletion was necessary in some patients, and in severe cases, intravenous replacement was required. Patients receiving ERBITUX therapy should be periodically monitored for hypomagnesemia, and accompanying hypocalcemia and hypokalemia during, and up to 8 weeks following the completion of, ERBITUX therapy.

Other serious adverse events associated with ERBITUX in clinical trials (n=774) were fever (5%), sepsis (3%), kidney failure (2%), pulmonary embolus (1%), dehydration (5% in patients receiving ERBITUX plus irinotecan, 2% receiving ERBITUX as a single agent) and diarrhea (6% in patients receiving ERBITUX plus irinotecan, 0.2% with ERBITUX as a single agent).

Additional common adverse events seen in patients receiving ERBITUX plus irinotecan (n=354) or ERBITUX as a single agent (n=420) were acneform rash (88%/90%), asthenia/malaise (73%/48%), diarrhea (72%/25%), nausea (55%/29%), abdominal pain (45%/26%), vomiting (41%/25%), fever (34%/27%), constipation (30%/26%) and headache (14%/26%).

Full prescribing information, including boxed WARNING regarding infusion reactions, is available upon request or by visiting www.ERBITUX.com.

References

    1. www-dep.iarc.fr. April 2002.

    2. Hunter KD et al. Profiling early head and neck cancer. Nat Rev
        Cancer. 2005 Feb; 5 (2): 127-35.

    3. Bourhis J and Pinto H. Redefining 'State of the Art' in Head
        and Neck Cancer. Oral presentation, 6th International
        Conference on Head and Neck Cancer 7-11 August 2004.

    4. Forastiere A, Koch W, Trotti A, Sidransky D, et al. Head and
        neck cancer. N Engl J Med 2001:345(26), 1890-1900.

About ImClone Systems Incorporated

ImClone Systems Incorporated is committed to advancing oncology care by developing and commercializing a portfolio of targeted biologic treatments designed to address the medical needs of patients with a variety of cancers. The Company's research and development programs include growth factor blockers and angiogenesis inhibitors. ImClone Systems' strategy is to become a fully integrated biopharmaceutical company, taking its development programs from the research stage to the market. ImClone Systems' headquarters and research operations are located in New York City, with additional administration and manufacturing facilities in Branchburg, New Jersey.

Certain matters discussed in this news release may constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 and the Federal securities laws. Although the company believes that the expectations reflected in such forward-looking statements are based upon reasonable assumptions it can give no assurance that its expectations will be achieved. Forward-looking information is subject to certain risks, trends and uncertainties that could cause actual results to differ materially from those projected. Many of these factors are beyond the company's ability to control or predict. Important factors that may cause actual results to differ materially and could impact the company and the statements contained in this news release can be found in the company's filings with the Securities and Exchange Commission including quarterly reports on Form 10-Q, current reports on Form 8-K and annual reports on Form 10-K. For forward-looking statements in this news release, the company claims the protection of the safe harbor for forward-looking statements contained in the Private Securities Litigation Reform Act of 1995. The company assumes no obligation to update or supplement any forward-looking statements whether as a result of new information, future events or otherwise.