OBJECTIVETo evaluate the antitumor efficacy, time to tumor progression (TTP) and toxicity of Iressa (ZD1839)-a selective epidermal growth factor receptor tyrosine kinase inhibitor in advanced non-small-cell lung cancer (NSCLC) patients who have failed to respond previous chemotherapy.

METHODSFifty-two patients with grade IV NSCLC previously treated with chemotherapy (77.0% of patients after second line therapy) received 250 mg of Iressa orally once daily until disease progression or development of intolerable toxic reaction. They were required to receive tumor-evaluation before the treatment, one month after Iressa administration and every other month thereafter.

RESULTSWithout complete regression being observed, partial response (PR) rate was 21.2% (11/52), stable disease (SD) 32.7% (17/52), disease control rate (PR + SD) 53.8%, progression of disease (PD) 46.2% (24/52); median time to tumor progression (TTP) was 3.5 month. Among them, 22 patients were followed up over one year and the 1-year survival rate was 31.8%. Symptomatic improvement rate was 52.9%. The most common adverse effects were skin reactions and diarrhea which were generally mild (grade 1 or 2). Only one patient withdrew from the trial because of grade III hepatic toxicity with increase in ALT and AST.

CONCLUSIONIressa has significant antitumor activity in advanced NSCLC patients who have previously failed in second or third line chemotherapy. It greatly alleviates tumor related symptoms. Adverse effects are generally tolerable. IRESSA is suitable for patients with poor performance status (ECOG > 2).