NCI Will Test New Drugs for Colorectal Cancer Throughout North America

National Cancer Institute
Monday, 28 June 1999

The National Cancer Institute (NCI) is launching a large research study that will test two of the most promising new drugs for metastatic colorectal cancer. The study will be conducted in hundreds of medical centers throughout the United States and Canada. Now beginning to enroll about 1,700 patients, the Cooperative Colorectal Cancer Combination Chemotherapy Clinical (6C) Trial will evaluate the new drugs -- CPT-11 and oxaliplatin -- as the initial therapy for advanced colorectal cancer. The drugs will be tested in combination with each other and with other drugs and these combinations will be compared with the current standard treatment for colorectal cancer.

Oxaliplatin and CPT-11 have each shown promise in earlier, separate studies. Used in combination with the drugs 5-fluorouracil (5-FU) and leucovorin (citrovorum factor), which are known to be effective in colorectal cancer, the combinations have shown higher response rates than 5-FU and leucovorin alone. The results are still too early to draw definitive conclusions about improved survival. Some studies have suggested that combinations of these drugs may be synergistic, boosting each other's effectiveness.

The 6C Trial will attempt to sort out which combinations and which methods of giving the drugs may result in better survival rates and the longest times to tumor progression, compared to the standard treatment. It will also yield important information about the side effects of the various combinations and about quality of life of patients on the different regimens.

"These are the first new drugs we have had to treat colorectal cancer in many years," said Barbara Conley, M.D., of NCI's Cancer Therapy Evaluation Program, "and this will be the first large, randomized North American study to evaluate both of these new agents. The results may move the treatment of colorectal cancer a significant step forward."

The trial will enroll patients with advanced (metastatic or recurrent) colorectal cancer. The patients will be divided randomly into six groups, as shown in the attached diagram.

One group will receive 5-FU and leucovorin, which are now widely considered the standard treatment in the United States. Two groups will receive this standard therapy plus CPT-11, and two other groups will receive the standard therapy plus oxaliplatin. The sixth group will receive oxaliplatin and CPT-11. (In the groups receiving the same drugs, investigators will compare different methods and schedules for administering them.)

The 6C Trial will take place in numerous cities and towns in virtually every part of the United States and in Canada. It will involve many of NCI's Clinical Trials Cooperative Groups, which are networks of institutions and researchers that conduct cancer trials jointly. Together, these groups have thousands of participating doctors.

"With this many institutions able to take part, we hope to complete enrollment in three years or less," said Michael O'Connell, M.D, chair of the North Central Cancer Treatment Group, which is leading the study. "This will enable us to answer key questions about these new treatments quickly, giving patients and their physicians much more information than they have now about the benefits and risks of the different regimens." O'Connell pointed out that the trial would also give researchers leads on how to design future trials to improve treatment further.

For more information, patients and physicians may call 1-800-4-CANCER or go to NCI's Web site for clinical trials, http://cancertrials.nci.nih.gov.

For more information, or to contact National Cancer Institute, see their website at: www.cancer.gov