ImClone Systems Incorporated today announced that its disease-directed Phase II clinical trial of IMC-A12, its anti-insulin-like growth factor-1 receptor (IGF-1R) monoclonal antibody, to treat advanced prostate cancer has commenced patient enrollment

NEW YORK, NY, USA | August 29, 2007 | ImClone Systems Incorporated (NASDAQ: IMCL), a leader in the development and commercialization of novel cancer therapeutics, today announced that its disease-directed Phase II clinical trial of IMC-A12, its anti-insulin-like growth factor-1 receptor (IGF-1R) monoclonal antibody, to treat advanced prostate cancer has commenced patient enrollment.

This Phase II single-arm, open-label study of IMC-A12 is enrolling asymptomatic, chemotherapy-naive patients with metastatic androgen-independent prostate cancer. A total of 30 patients are expected to be enrolled. This Phase II study is designed to evaluate the efficacy, safety and pharmacology of IMC-A12 administered every two weeks by intravenous infusion.

"We are very excited about beginning another disease-directed, proof-of-concept trial of IMC-A12 in advanced prostate cancer, which is based on a solid foundation of preclinical and translational studies performed by ImClone and academic collaborators, suggesting that IMC-A12 has the ability to disrupt the biological processes responsible for prostate cancer cell growth and survival," said John H. Johnson, Chief Executive Officer of ImClone Systems.

"This study is specifically designed to detect appreciable activity in relatively untreated patients, and, if positive, the results may serve as a rationale for additional registrationally-directed studies in early- and advanced-stage disease," said Eric K. Rowinsky, M.D., Chief Medical Officer and Executive Vice President of ImClone Systems.

IMC-A12 is a fully human IgG1Mab that is designed to specifically target the human insulin-like growth factor type 1 receptor, thereby inhibiting certain ligands known as insulin-like growth factors I and II from binding to and activating the receptor. This action blocks a signaling pathway that enhances tumor cell proliferation and survival.

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 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.

SOURCE: ImClone Systems Incorporated