May 1, 2003
Cancer Drug Iressa Should Not Be Approved, Public Citizen Tells FDA
Trials Do Not Show a Benefit to Patients; Drug Tied to 173 Deaths from Acute Lung Disease in Japan
WASHINGTON, D.C. – Data showing that AstraZeneca’s new cancer drug Iressa (gefitinib) is likely ineffective and dangerous should dissuade the U.S. Food and Drug Administration (FDA) from approving the drug for use in the United States, Public Citizen said today in a letter to the agency.
AstraZeneca has sought an accelerated approval for gefitinib under a system developed by the FDA to approve drugs more quickly if they treat serious or life-threatening diseases for which no other treatment is available. However, results of clinical trials suggest that gefitinib will have to be removed from the market soon after approval.
In two well-designed studies of patients who had not received prior therapy for cancer, there was no difference in the one-year survival in those taking gefitinib and those taking a placebo. A third study, which was submitted to the FDA as the basis for approval of the drug, was flagged as problematic by members of an FDA review team and the team leader. The study tested an atypical group of patients with less aggressive cancers, did not have a control group, and did not adequately separate the effects of gefitinib from the effects of other medications the patients were taking.
"The FDA would be putting patients in jeopardy by approving a drug that is already showing itself to be ineffective and dangerous. The agency certainly should not approve it on a faster timetable," said Sidney Wolfe, M.D., director of Public Citizen’s Health Research Group. "The severity of adverse events, both in the clinical trials and in Japanese patients, should be a red alert to the agency."
In the study AstraZeneca submitted to support the drug’s approval, 25 percent of patients suffered from pneumonia or acute respiratory disease, and one patient died from each condition.
Japan approved gefitinib in July 2002. In February 2003, AstraZeneca Japan announced that of about 23,500 patients who had been prescribed the drug, 473 had developed serious lung disease or pneumonia and 173 had died. It is likely, however, that many more patients became sick or died after taking the drug because only a small proportion of cases are both properly diagnosed and reported, Public Citizen said.
Under the FDA’s accelerated approval process, drugs are often approved on the basis of a clinical finding, such as shrinkage of a tumor, that does not necessarily mean the patient will be cured or live longer. The company is then required to conduct post-marketing studies to determine if the approval was appropriate and whether the drug provides a true benefit to patients. The two studies that have already been conducted would normally have been done and submitted during the post-marketing period. Because the studies already have been conducted and show no benefit associated with the drug, the FDA cannot justify approving the drug, Public Citizen said.
"The FDA’s medical officer has expressed grave reservations about the studies that AstraZeneca is relying on to push this approval – with good reason," Wolfe said. "It would be inexcusable to approve a drug for patients that shows a high likelihood of causing deadly lung disease in addition to doing next to nothing to stop cancer."
Click here to view a copy of Public Citizen’s letter to the FDA.