June 17, 2005 — The U.S. Food and Drug Administration (FDA) has notified the public via health advisory of new limitations to the use of gefitinib (Iressa tablets, made by AstraZeneca) in cancer patients with non-small cell lung cancer (NSCLC), according to an alert sent today from MedWatch, the FDA's safety information and adverse event reporting system.
The newly approved labeling states that gefitinib should only be used in patients who are currently benefiting or have previously benefited from its use. Unlike newer drugs, gefitinib has not demonstrated a survival benefit in clinical studies.
The epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor was granted accelerated approval by the FDA in May 2003 for the treatment of NSCLC that is refractory to established cancer therapies (a platinum drug and docetaxel). Conditions for approval required only that efficacy be demonstrated for a surrogate endpoint; in clinical studies, treatment with gefitinib yielded a tumor response rate of approximately 10%.
The current limitation was based on an FDA analysis of data from two failed clinical trials that were conducted as a condition of the approval.
The first trial involved 1,692 patients with regionally advanced or metastatic NSCLC who had failed one or two prior regimens. Results showed that gefitinib was not associated with any significant survival benefit in the overall study population nor in patients with high levels of EGFR relative to placebo.
In the second trial, gefitinib also showed no benefit over placebo when administered after completion of induction and consolidation chemotherapy and radiation therapy in patients with stage III NSCLC.
In contrast, erlotinib (Tarceva tablets, made by OSI Pharmaceuticals, Inc.) was approved by the FDA last November on the basis of clinical study results showing that it improved survival in patients with NSCLC relative to placebo. Furthermore, the presence of EGFR at high levels appeared to predict a good response to erlotinib therapy.
Distribution of gefitinib will be limited under a risk management plan (Iressa Access Program) to patients that show or have shown benefit from its use and patients previously or newly enrolled in noninvestigational new drug trials that were approved by an Investigational Review Board prior to today.
New patients may be able to obtain gefitinib by meeting the criteria for trial enrollment if the company decides to make it available under investigational new drug.
The FDA notes that the Agency is not considering market withdrawal of gefitinib at this time. The future role of the drug will be determined by an analysis of data from ongoing clinical trials and trials currently in development.
Adverse events related to the use of gefitinib should be reported to the FDA's MedWatch program by telephone at 1-800-FDA-1088, by fax at 1-800-FDA-0178, online at https://www.fda.gov/medwatch, or by mail to 5600 Fishers Lane, Rockville, MD 20852-9787.
Reviewed by Gary D. Vogin, MD
Medscape Medical News © 2005 Medscape
Cite this: Yael Waknine. FDA Limits Use of Iressa for Non-Small Cell Lung Cancer - Medscape - Jun 17, 2005.