'Targeting' the epidermal growth factor receptor tyrosine kinase with gefitinib (Iressa) in non-small cell lung cancer (NSCLC)

Gefitinib (ZD1839, Iressa), a selective drug inhibitor of the epidermal growth factor receptor (EGFR) tyrosine kinase (TK), was recently approved for the treatment of patients with advanced non-small cell lung cancer (NSCLC). This article reviews the identification of EGFR as a therapeutic target and the steps in the development of gefitinib as "targeted" monotherapy for patients with NSCLC. Whether EGFR is required for the maintenance of lung tumor survival is also discussed. Finally, strategies to identify predictors of response to gefitinib are explored.