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This study is the first of an initial stage of at least 10 Phase I and II clinical trials of IMC-A12 sponsored by the Cancer Therapy Evaluation Program (CTEP) of the Division of Cancer Treatment and Diagnosis (DCTD), National Cancer Institute (NCI), to commence patient enrollment. ImClone announced the selection of these proposals by NCI in September 2007.

The insulin-like growth factor (IGF) system plays a critical role in the development and progression of many types of cancer, including many pediatric-specific cancers. The initial Phase I study, which will be performed by the COG Phase I Consortium that includes 20 clinical COG sites in North America, will determine the optimal dose, side effects, pharmacology, and biological effects of IMC-A12 administered intravenously once each week to children and adolescents with relapsed or refractory solid cancers. Up to 38 patients are expected to be enrolled. Immediately upon determination of a recommended pediatric Phase II dose for IMC-A12, the antitumor activity of IMC-A12 will be evaluated in a much larger Phase II study in a larger number of COG sites. The Phase II study will evaluate the antitumor activity of IMC-A12 in multiple pediatric malignancies, including osteosarcoma, Ewing's sarcoma/peripheral primitive neuroectodermal tumor (PNET), rhabdomyosarcoma, Wilms' tumor, and others.

"We are pleased to initiate the first of a series of NCI-sponsored IMC-A12 trials and are particularly excited about this pediatric study, as it is one of the first such studies of an IGF-IR inhibitor ever undertaken in pediatric patients with cancer," said Eric K. Rowinsky, M.D., Chief Medical Officer and Executive Vice President of ImClone Systems. "Evaluations of new cancer therapies in children usually occur long after studies in adults and it is very gratifying to begin directed studies of IMC-A12 in both adult and pediatric patients at nearly the same time."

IMC-A12 is a fully human IgG1 monoclonal antibody. It is designed to specifically target the human IGF-1R, thereby inhibiting certain ligands known as IGFs I and II from binding to and activating the receptor. This action blocks a signaling pathway that enhances tumor cell proliferation and survival. In 2007, ImClone completed enrollment into two Phase I studies of IMC-A12, which demonstrated favorable safety and pharmacokinetic profiles, as well as preliminary evidence of antitumor activity as a single agent when administered either weekly or every two weeks. In addition to the studies of IMC-A12 in pediatric patients with advanced malignancies, Phase II studies of IMC-A12 in patients with advanced prostate and colorectal cancers have begun to enroll patients.

About ImClone's NCI-sponsored IMC-A12 Trials

In September 2007, the CTEP of the DCTD, NCI selected 10 proposals for Phase I and II clinical trials of ImClone's IMC-A12, and several other proposals have been selected since that time. The selection of the proposed trials followed NCI's solicitation for specific disease-directed studies among NCI investigators at academic institutions, clinical trial consortia and NCI-sponsored oncology cooperative clinical trial groups in the U.S. The selected trials represent the first stage of clinical evaluations of IMC-A12 sponsored by CTEP, NCI under a Clinical Trials Agreement between ImClone Systems and DCTD, NCI to facilitate the clinical development of IMC-A12. Both randomized and nonrandomized Phase II trials sponsored by CTEP will explore the clinical activity, pharmacology and biological effects of IMC-A12 as a single agent or combined with other relevant anticancer agents in a wide range of malignancies including breast, lung, pancreas and liver cancers, as well as both adult and pediatric sarcomas. In addition, Phase I/II studies will evaluate the safety, pharmacology, anticancer activity and biological effects of IMC-A12 in children and adolescents with cancer, as well as in combination with other novel targeting agents in which there is a specific rationale for combined use.

About ImClone Systems

ImClone Systems Incorporated is a fully integrated biopharmaceutical company 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' headquarters and research operations are located in New York City, with additional administration and manufacturing facilities in Branchburg, New Jersey. For more information about ImClone Systems, please visit the Company's web site at

http://www.imclone.com

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 currently expected. 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, particularly those factors identified as "risk factors" in the Company's most recent annual report of Form 10-K and in its quarterly reports on Form 10-Q and current reports on Form 8-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.

SOURCE: ImClone Systems Incorporated

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