Purpose : To establish the feasibility and tolerability of gefitinib (ZD1839, Iressa) with radiation (RT) or concurrent chemoradiation (CRT) with cisplatin (CDDP) in patients with advanced non small cell lung cancer (NSCLC).Patients and Methods : In this multicenter Phase I study, 5 patients with unresectable NSCLC received 250 mg gefitinib daily starting 1 week before RT at a dose of 63 Gy (Step 1). After a first safety analysis, 9 patients were treated daily with 250 mg gefitinib plus CRT in the form of RT and weekly CDDP 35 mg/m(2) (Step 2). Gefitinib was maintained for up to 2 years until disease progression or toxicity.Results : Fourteen patients were assessed in the two steps. In Step 1 (five patients were administered only gefitinib and RT), no lung toxicities were seen, and there was no dose-limiting toxicity (DLT). Adverse events were skin and subcutaneous tissue reactions, limited to Grade 1-2. In Step 2, two of nine patients (22.2%) had DLT. One patient suffered from dyspnea and dehydration associated with neutropenic pneumonia, and another showed elevated liver enzymes. In both steps combined, 5 of 14 patients (35.7%) experienced one or more treatment interruptions.Conclusions : Gefitinib (250 mg daily) in combination with RT and CDDP in patients with Stage HI NSCLC is feasible, but CDDP likely enhances toxicity. The impact of gefitinib on survival and disease control as a first-line treatment in combination with RT remains to be determined. (C) 2011 Elsevier Inc.