Molecular and clinical subgroup analyses from a phase III trial comparing gefitinib with docetaxel in previously treated non-small cell lung cancer (INTEREST)

Abstract

8001 Background: In INTEREST, gefitinib demonstrated non-inferior overall survival (OS), more favorable tolerability and improved QoL vs docetaxel in advanced pretreated NSCLC. We examined potential clinical and biomarker correlations with efficacy. Methods: Pre-defined clinical subgroups included histology, performance status, prior platinum and paclitaxel therapy, number of prior regimens, smoking history, gender, and ethnicity. Tumor tissues were evaluated by FISH, IHC, direct-gene sequencing and PCR for EGFR gene-copy number, EGFR protein expression, EGFR and K-Ras gene mutation, respectively. The OS effect was compared between subgroups using treatment-by-covariate interaction tests. OS and progression-free survival (PFS) were compared between treatments within subgroups using Cox proportional hazards models and objective response rate (ORR) using logistic regression models. Results: OS results were consistent in all clinical subgroups except for the number of prior regimens (interaction test P=0.03,...