Global standards should be applied to drug evaluation.

Apanel of experts appointed by the Ministry of Health, Labor and Welfare to re-evaluate the benefits and potential adverse effects of Iressa, a drug used to treat certain types of lung cancer, concluded doctors should be allowed to use the medicine ``with due caution'' for the time being.

Even though an international clinical trial conducted by the manufacturer did not confirm Iressa helps lung cancer patients to live longer, the tests showed that it had indeed been effective, albeit slightly, for Malaysian and other Asian patients. Although the clinical trial did not cover Japan, where nearly 600 patients have died from possible side effects of the drug, a separate study suggested Iressa works well with Japanese patients.

The health ministry's panel recommended that Iressa be administered with great care by doctors well-versed in cancer drugs and only after offering comprehensive explanations to patients about the effects, risks and limitations of the medicine.

Although some patients treated with Iressa died, others with deadly cancer recovered to the extent that they could return to work. The panel had to make a difficult decision. We support the panel's decision on allowing the drug to be used under certain conditions.

Iressa is a new type of cancer drug that inhibits the working of a protein that promotes growth and multiplication of cancer cells. It is administered only to patients in the late stages of a deadly form of lung cancer that has not responded to other anti-cancer drugs. It was initially touted as a new wonder drug.

Nearly 90,000 patients have been treated with Iressa in just two and a half years since it became widely available. Experts have pointed out that the drug, which is taken orally, has been overused, resulting in a high death toll.

Such sharply divided opinions among experts about one drug must bewilder many people. One of the reasons for this confusion is a Japanese way of clinical tests for cancer drugs.

Ordinary drugs are approved by the authorities after a three-stage clinical trial. The first phase is to check safety and the second is to examine a drug's effects on a small number of patients. The third phase is to evaluate the overall effectiveness in tests involving a large number of patients.

Anti-cancer drugs can be approved if they are found to cause cancer cells to shrink in the second phase. The third phase to test the life-extending effectiveness can be conducted once approval is given.

Iressa was approved for use first in Japan in 2002 after second-phase tests showed the drug could shrink tumors. The results of the ongoing third-phase test involving many cancer patients to determine whether the drug in fact has a survival advantage will not be known until 2007.

The situation is different in Europe. There, approval of anti-cancer drugs requires the results of a third-phase clinical trial showing prolonged survival. European trials of Iressa showed no survival benefit, and the manufacturer has since withdrawn its application.

In the United States, Iressa was approved after the second phase of the trial, just like Japan. But subsequent clinical testing on a large number of patients failed to show a survival advantage, and the U.S. Food and Drug Administration is now considering whether Iressa should be withdrawn from the market or if other regulatory actions are appropriate.

The world trend in anti-cancer drug approval focuses on effectiveness in improving survival as well as in shrinking tumors. The health ministry should pay serious attention to this trend in its ongoing review of the guidelines for clinical trials of anti-cancer drugs.

This stance was also echoed in a report published last autumn by Japan Society of Clinical Oncology, which urged the government to approve drugs for such common cancers as lung and breast cancer according to criteria focused on survival benefit. The ministry should heed this opinion from the academic community.

In this age of rapid progress in pharmaceutical and medical sciences, announcements of the development of new anti-cancer drugs come thick and fast. That demands greater care in evaluating the safety and effectiveness of new drugs before they are used widely.

--The Asahi Shimbun, Jan. 25(IHT/Asahi: January 26,2005)