[Iressa (gefitinib)].

Gefitinib is an epidermal growth factor receptor (EGFR) inhibitor that is reported to be well tolerated and active in patients with chemotherapy-resistant non small cell lung cancer. On the other hand, gefitinib was also reported to produce a severe adverse event, interstitial lung disease, in less than 2% of treated patients. Given these circumstances, it is important to evaluate this drug and to establish its use clinically. We do not have sufficient data to evaluate gefitinib at this time. Phase III study of second/third line or maintenance therapy using gefitinib is required for such an evaluation. The development of individualized therapy with gefitinib might be also be required.