A phase II randomized trial evaluating gefitinib intercalated with pemetrexed/platinum chemotherapy or pemetrexed/platinum chemotherapy alone in unselected patients with advanced non-squamous non-small cell lung cancer

Abstract

Current pemetrexed/platinum chemotherapy does not produce a satisfactory therapeutic response in advanced lung cancer patients. The aim of this study was to determine whether the administration of gefitinib, a tyrosine kinase inhibitor (TKI), intercalated with pemetrexed/platinum could improve the efficacy in chemotherapy-naïve patients with advanced non-squamous NSCLC without subsequent gefitinib maintenance therapy. Treatment-naïve patients with stage IIIB or IV NSCLC were randomly assigned to receive pemetrexed (500 mg/m (2) d1) and either cisplatin (75 mg/m (2) d1) or carboplatin (AUC = 5 d1) plus gefitinib (250 mg/d on days 3 to 16 of a 3-week cycle) (PC-G) or pemetrexed-platinum (PC) alone. Randomization was stratified according to the tobacco smoking status and EGFR mutational status of the patients. The primary endpoint was the non-progression rate (NPR) at 12 weeks. Secondary endpoints included progression-free survival (PFS), overall response rate (ORR), overall survival (OS), and biosafety. The NPR at 12 weeks was 84.5% for the PC-G treatment arm and 83.1% for the PC treatment arm (P = 0.87). Median PFS was 7.9 months for the PC-G arm and 7.0 months for the PC arm (P = 0.57). The ORR was 50.0% for the PC-G arm and 47.4% for the PC arm (P = 0.78). Median survival was 25.4 mo for the PC-G arm and 20.8 mo for the PC arm (P = 0.54). The incidence of adverse events was similar between the two treatment arms, except for a higher incidence of skin rash with PC-G. Predefined subgroup analyses demonstrated that PC-G significantly increased the PFS compared with the PC regimen in patients with EGFR mutations (P = 0.017). Although gefitinib intercalated with pemetrexed/platinum chemotherapy did not improve the NPR at 12 weeks compared with chemotherapy, an improvement in the PFS for the intercalated treatment arm was seen in the subgroup of patients with EGFR mutations.

Keywords: EGFR mutations; gefitinib; non-small cell lung cancer; non-squamous; pemetrexed; phase II randomized trial; platinum.

Figure 1. Patient disposition up to December 31, 2012, cutoff date of this analysis.

Figure 2. Kaplan–Meier plots of progression-free survival (PFS) in both treatment groups. (A) PFS for all NSCLC patients; (B) PFS for never smokers; (C) PFS for current or ex-smokers; (D) PFS for patients with EGFR mutant; (E) PFS for patients with wild-type EGFR; (F) PFS for patients with unknown EGFR status; (G) Kaplan–Meier plots of overall survival (OS) in both treatment groups. Abbreviations: PC, pemetrexed plus either cisplatin or carboplatin; G, gefitinib; HR, hazard ratio.