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FDA restricts use of cancer drug Iressa

AstraZeneca announced that after discussions with the FDA ( U.S. Food and Drug Administration ), the company is making a labeling change to Iressa ( Gefitinib ).

Based on the FDA's assessment of currently available data, including the lack of survival benefit in the Phase III Trial 709 ( ISEL ) comparing Iressa to placebo in advanced recurrent non-small-cell lung cancer ( NSCLC ), and the availability of other treatment options in the United States that do prolong life, Iressa is only to be used in patients who have previously taken Iressa and are benefiting or have benefited from Iressa.

In addition, Iressa will continue to be available for use in clinical trials approved by an Institutional Review Board ( IRB ) prior to June 17, 2005.
Clinical trials approved by an IRB after June 17, 2005, must be conducted under an investigational new drug application ( IND ).

To implement the new label, as of September 15, 2005, AstraZeneca will initiate the Iressa Access Program to fill renewal prescriptions for Iressa through a single mail order pharmacy for patients meeting the criteria set forth by the label.
Iressa will remain available in the United States, through the Iressa Access Program, for patients who are currently benefiting or who have benefited, pending availability of new data that would support an additional revision to the label, or possible future withdrawal.
Approximately 4,000 patients currently are taking Iressa in the United States.

Iressa is approved in the United States under accelerated approval by the FDA that enabled the drug to be approved on the basis of adequate and well-controlled clinical trials establishing that the drug product had an effect on a surrogate end point likely to predict clinical benefit in a serious or life threatening illness for which there is an unmet medical need.

The Phase III study called ISEL, or trial 709, released in December 2004 showed that IRESSA did not produce a statistically significant survival advantage over placebo in patients with advanced NSCLC.

AstraZeneca is continuing to evaluate potential predictive biomarkers to better identify more readily those patients who are most likely to benefit from Iressa. AstraZeneca is committed to continuing Iressa research and to validating the emerging science in controlled clinical trials.

Iressa is approved in the United States for use as monotherapy for the continued treatment of patients with locally advanced or metastatic non-small-cell lung cancer ( NSCLC ) after failure of both platinum-based and Docetaxel chemotherapies who are benefiting or have benefited from Iressa.
For other patients, in light of positive survival data with other agents, physicians should use other treatment options.
The effectiveness of Iressa was initially based on objective response rates. Subsequent studies intended to demonstrate an increase in survival have been unsuccessful.

The most frequent drug-related adverse events associated with Iressa were diarrhea ( 48% ) sometimes associated with dehydration, rash ( 43% ), acne ( 25% ), dry skin ( 13% ), nausea ( 13% ), and vomiting ( 12% ).
These events generally occurred within the first month of therapy and usually were mild to moderate. 2% of patients stopped taking Iressa due to an adverse drug reaction.
Infrequent cases ( about 1% ) of interstitial lung disease ( ILD - described as interstitial pneumonia, pneumonitis, and alveolitis ) have been observed in patients receiving Iressa.
Approximately 1/3 of the ILD cases were fatal. When ILD occurred, it was often accompanied by acute onset of breathing difficulty with cough or low-grade fever requiring hospitalization.
Iresssa may cause fetal harm if administered to a pregnant woman.
Asymptomatic increases in liver enzymes and eye irritation have also been observed in patients receiving Iressa.
Increases in bleeding events have been observed in cancer patients taking Warfarin and Iressa.

Source: AstraZeneca, 2005