Drug Shows Promise for Treating Advanced Colorectal Tumors

FOR EMBARGOED RELEASE: May 12, 2001 11:00am PST ASCO Abstract #7

Contact: Christine Hickey212-639-3573At ASCO: 917-270-2916 (cell)917-641-4291 (beeper)

Drug Shows Promise for Treating Advanced Colorectal Tumors Resistant to Standard Treatment

Monoclonal Antibody Targets Epidermal Growth Factor Receptor

San Francisco, CA, May 12, 2001 - A new drug for the treatment of advanced-stage colorectal cancer can shrink tumors in some patients who have developed resistance to other chemotherapy agents. The results of the study of IMC-C225 (cetuximab), led by Dr. Leonard Saltz of Memorial Sloan-Kettering Cancer Center, were reported today at the American Society of Clinical Oncology's Annual Meeting in San Francisco.

"This is a significant result," said Dr. Saltz. "We have a group of patients who have failed to respond to two other therapies, and now we're getting a 22.5 percent response rate from this new regimen."

In the phase II trial, IMC-C225 was given to 120 patients with metastatic (widespread) colorectal cancer whose tumors no longer responded to the standard chemotherapy agent irinotecan (CPT-11). Patients were given the same dose of CPT-11 that they had previously received plus IMC-C225, and 22.5 percent of them had their tumors shrink 50 percent or more. An additional 7.5 percent achieved stable disease.

IMC-C225 is a member of a class of drugs targeted against the epidermal growth factor (EGF) receptor, a cell surface structure. IMC-C225 is a monoclonal antibody that blocks that receptor, making it harder for tumor cells to reproduce. Researchers believe that IMC-C225 works by making cancer cells more vulnerable to other chemotherapy drugs. All of the patients in the study had tumors that tested positive for the EGF receptor. Another important finding was that of more than 400 colon cancer patients tested, 72 percent of tumors expressed the EGF receptor, a much higher number than expected.

Patients given IMC-C225 had few side effects from the drug. The most common one was an acne-like skin rash, which occurs because skin cells also contain large amounts of EGF receptors. "Patients still had side effects from the other chemotherapy drugs they were given," Dr. Saltz said, "but IMC-C225 did not seem to increase those side effects."

According to Dr. Saltz, IMC-C225 is a good example of the next wave in cancer-drug development: targeted therapies based on an intricate understanding of the cancer cell. "Basic science has achieved such progress in terms of our understanding of how cells work that we now have therapies based on that knowledge," Dr. Saltz said. "The idea that we can identify an EGF receptor, understand what it does, and what might happen if we block it, is exactly the kind of paradigm we're going to see more of in the future -- elegant science translated into useful therapies."

The current study was done in collaboration with several other US centers and was supported by ImClone Systems Incorporated, which manufactures IMC-C225. Dr. Saltz is leading other studies of IMC-C225 in colorectal cancer, and later this year will begin a large scale, randomized multi-center phase III trial to test IMC-C225 in combination with other chemotherapy drugs as part of a first-line treatment for advanced-stage colorectal cancer (before patients develop resistance). For further information on clinical trials with IMC-C225, contact ImClone Systems Incorporated at (877) 925-6631.

Colorectal cancer is the second leading cause of cancer death, with an estimated 56,300 men and women expected to die this year in the United States alone.

Memorial Sloan-Kettering Cancer Center is the world's oldest and largest institution devoted to prevention, patient care, research and education in cancer. Our scientists and clinicians generate innovative approaches to better understand, diagnose and treat cancer. Our specialists are leaders in biomedical research and in translating the latest research to advance the standard of cancer care worldwide.

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