Gefitinib Superior to Doublet Chemotherapy in Phase III Asian First-Line Advanced NSCLC Study

Data presented at the European Society of Medical Oncology (ESMO) meeting in Stockholm show that the IRESSA Pan-ASia Study (IPASS) exceeded its primary objective, demonstrating superior progression-free survival (PFS) for oral gefitinib (Iressa), compared with intravenous carboplatin/paclitaxel chemotherapy (hazard ratio [HR] = 0.74, P < .0001) in the overall population of clinically selected patients with advanced non–small-cell lung cancer (NSCLC) in Asia.

In preplanned analyses of subgroups defined by the biomarker status of the patient’s tumor, PFS was significantly longer for gefitinib than chemotherapy in patients with epidermal growth factor receptor (EGFR) mutation–positive tumors (HR = 0.48, P < .0001), and significantly longer for chemotherapy than gefitinib in patients with EGFR mutation–negative tumors (HR = 2.85, P < .0001). In the subgroup of patients whose EGFR mutation status was unknown, PFS was superior for gefitinib, consistent with the overall population. Gefitinib also demonstrated a more favorable tolerability profile and superior quality-of-life improvement rates vs chemotherapy.

Noninferiority Objective

IPASS was an open-label, randomized, parallel-group study that assessed the efficacy, safety, and tolerability of gefitinib vs carboplatin/paclitaxel as first-line treatment in a selected population of patients from Asia. The primary endpoint was PFS, with the objective of demonstrating that gefitinib was noninferior to carboplatin/paclitaxel therapy. The study enrolled 1,217 Asian patients with advanced NSCLC who had not received prior chemotherapy for advanced disease, whose tumors were adenocarcinomas, and who either had never smoked or were former light smokers.

Lead investigator Professor Tony Mok, of Hong Kong Cancer Institute, Chinese University of Hong Kong, said, “Results from the IPASS study mean that gefitinib. . . offers a potential new paradigm in the first-line treatment of selected Asian patients with advanced NSCLC.”