WASHINGTON — A new drug for patients with advanced colon cancer has been found effective enough in tests that the National Cancer Institute and the Food and Drug Administration have decided to make it generally available before the study results are published in a medical journal.
The drug does not cure cancer but appears to extend patients' lives. Neither the researchers nor government officials would disclose how much time patients gained. The added survival time, which could be a matter of months, is to be published later in a medical journal.
Colon cancer is the second-leading cause of cancer death in the United States, after lung cancer. The American Cancer Society estimates there will be 107,000 new cases of colon cancer this year and 53,500 deaths.
Normally, a new drug is not made generally available until after evidence of its safety and effectiveness has been published in the medical literature where independent experts can examine it and sometimes spot flaws that invalidate the findings. The government's decision highlights a growing debate among medical researchers as to how much evidence is needed before extending a putatively beneficial treatment to all who might benefit.
Stimulates Immune System
The FDA has approved a proposal by NCI under which the drug levamisole will be available for post-surgical treatment of cancer that has penetrated the colon wall or has already spread to the lymph nodes. The drug, which stimulates the immune system to fight tumors and is manufactured by Janssen Pharmaceutica Inc., is used in conjunction with another drug, 5-fluorouracil (5-FU).
More than half of those diagnosed with colon cancer will have tumors that have already spread to some extent, making them more likely candidates for the new drug. Although the cancer is curable in its earliest stages, only 40% of later-stage colon cancer victims now live for at least five years.
Five Years of Trials
The levamisole trials have been under way for about five years, conducted by the North Central Cancer Treatment Group under the direction of Charles Moertel of the Mayo Clinic.
Results of a preliminary trial involving 408 patients are awaiting publication in the Journal of Clinical Oncology. Analysis of a larger trial of about 1,300 patients is just beginning. However, word that the results of the trials were positive has been circulating among leading cancer specialists for months.
NCI Director Samuel I. Broder defended the decision. "In studies which the NCI supports . . . patient's primary duty is to get better," he said, adding that if researchers learn information that could benefit patients, it should not be withheld from them under the theory that the greater good of society depends on completing the study as planned.