Gefitinib (ZD1839, Iressa®) in non-small-cell lung cancer: A review of clinical trials from a daily practice perspective

Gefitinib (ZD1839) is the most widely studied targeting agent in the area of non-small-cell lung cancer (NSCLC). Gefitinib is an orally active epidermal growth factor receptor (EGFR) tyrosine kinase (TK) inhibitor. In order to assess the role of gefitinib in the management of NSCLC patients, we systematically reviewed published clinical trials from a daily practice perspective. A systematic research was made in the international medical literature. Gefitinib demonstrated a good tolerance and an encouraging efficacy in pretreated NSCLC patients in preclinical studies. These results were then confirmed in two phase II trials (IDEAL 1 and 2) involving more than 400 patients mostly pretreated with a platinum-containing regimen and docetaxel. All these results were reinforced by those of retrospective studies on patients enrolled in a compassionate use programme. Thus, two phase III trials in chemo-naive patients were initiated (INTACT 1 and 2). Unfortunately, the use of gefitinib with standard combination chemotherapy provided no survival benefit nor response rate or progression-free survival improvement over placebo. Furthermore, we also reviewed the results of studies interested in the characterization of predictive clinical or biological markers for response to gefitinib and discussed the results obtained with other EGFR inhibitors. The efficacy of gefitinib in the first-line setting of each stage of NSCLC has to be further studied through clinical trials. Furthermore, translational studies characterizing the molecular features involved in the response to anti-EGFR-targeted therapies are needed.