ImClone Systems Incorporated today announced that its disease-directed Phase 2 clinical trial in patients with advanced prostate cancer randomized to treatment with either IMC-A12 or IMC-1121B plus mitoxantrone and prednisone has commenced patient enrollment

NEW YORK, NY, USA | August 26, 2008 | ImClone Systems Incorporated (NASDAQ: IMCL), a global leader in the development and commercialization of novel antibodies to treat cancer, today announced that its disease-directed Phase 2 clinical trial in patients with advanced prostate cancer randomized to treatment with either IMC-A12 or IMC-1121B plus mitoxantrone and prednisone has commenced patient enrollment. IMC-A12 and IMC-1121B are two therapeutic candidates in ImClone’s proprietary receptor-targeted antibody pipeline. IMC-A12 is ImClone’s fully human, IgG1 anti-insulin-like growth factor-1 receptor (IGF-1R) monoclonal antibody and IMC-1121B is its fully human, IgG1 anti-vascular growth factor receptor-2 (VEGFR-2) monoclonal antibody.

This multicenter, randomized open-label Phase 2 single-arm study is enrolling patients with metastatic androgen-independent prostate cancer who have developed disease progression during or within 60 days of receiving docetaxel-based chemotherapy or demonstrated intolerance to docetaxel-based therapy. A total of 132 patients are expected to be enrolled at various centers, including those that participate in the Department of Defense’s Prostate Cancer Consortium. This Phase 2 study is designed to evaluate the efficacy and safety of both IMC-A12 and IMC-1121B combined with mitoxantrone and prednisone. IMC-A12 and IMC-1121B are administered weekly, whereas mitoxantrone is administered every three weeks with oral daily prednisone.

"We are very pleased about beginning another disease-directed, proof-of-concept trial which efficiently evaluates two of our pipeline antibodies with distinct mechanisms of action, yet each with potential applicability in the treatment of prostate cancer based on preclinical investigations performed by ImClone and academic collaborators," said Eric K. Rowinsky, M.D., Chief Medical Officer and Executive Vice President of ImClone. "The results of any one of the study arms, or even both, in conjunction with those of other ongoing clinical and preclinical studies, may serve as platforms for subsequent registration directed activity in several early- and advanced-stage prostate cancer settings."

IMC-A12 is a fully human IgG1 monoclonal antibody designed to specifically target the human IGF-1R, thereby inhibiting certain ligands known as IGFs 1 and 2 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 1 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 this Phase 2 study announced today, Phase 2 studies of IMC-A12 in adult and adolescent patients with soft tissue sarcoma, untreated advanced prostate, pancreatic, colorectal, liver, and head and neck cancers, as well as a series of Phase 1/2 studies in pediatric malignancies and another evaluating the combination of IMC-A12 and temsirolimus, have begun to enroll patients.

IMC-1121B is a fully human IgG1 monoclonal antibody designed to bind to the extracellular domain of VEGFR-2 found on tumor vasculature, thereby inhibiting certain ligands known as vascular endothelial growth factors from binding to and activating the receptor. This action blocks a signaling pathway key to new blood vessel formation in growing tumors, which has been shown to starve tumors of their nutrient supply and result in significant tumor growth inhibition in pre-clinical models. In addition to this Phase 2 study announced today, disease-directed studies of IMC-1121B in patients with advanced melanoma, liver and renal cancers have begun to enroll patients, and additional Phase 2 and 3 evaluations are in various stages of development. In April 2008, ImClone announced an agreement with the Food and Drug Administration on a Special Protocol Assessment for a Phase 3 study of IMC-1121B in women with metastatic breast cancer, which recently commenced.

About ImClone Systems

ImClone Systems Incorporated is a fully integrated global 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.

SOURCE: ImClone Systems Incorporated