First-iGAP: A Randomized Placebo-Controlled Phase II Study of First-line Intercalated Gefitinib and Pemetrexed-Cisplatin Chemotherapy for Never-Smoker Lung Adenocarcinoma Patients.

ABSTRACT

BACKGROUND: We aimed to evaluate whether intercalated combination of EGFR tyrosine kinase inhibitor gefitinib and chemotherapy improves survival outcomes in never-smokers with advanced lung adenocarcinoma. PATIENTS AND METHODS: Never-smokers with chemo-naive stage IIIB/IV lung adenocarcinoma were randomly assigned to receive either gefitinib or placebo on days 5 to 18 of a 3-weekly cycle of pemetrexed and cisplatin. Chemotherapy was given up to 9 cycles, after which gefitinib or placebo was given daily. Patients in the placebo arm who had progression were crossed over to receive gefitinib. RESULTS: Between June 2012 and December 2014, 76 patients with median age of 58.0 years were randomized, 39 on gefitinib and 37 on the placebo arm. EGFR mutation was positive in 34 (44.7%) patients. Baseline characteristics were well balanced between the 2 arms. The gefitinib arm had a better response rate (79.5% vs. 51.4%, P = .010) and median progression-free survival (PFS) (12.4 vs. 6.7 months, hazard ratio [HR] 0.49, P = .005) than the placebo arm; however, there was no statistically significant difference in median overall survival between the 2 arms (31.8 vs. 22.9 months, HR 0.78, P = .412). The PFS benefit of intercalated use of gefitinib over placebo was more apparent for patients with EGFR-mutant tumors (13.3 vs. 7.8 months, P = .025) than those with EGFR-wild-type tumors (8.2 vs. 6.6 months, P = .063). Overall, there was no difference in the frequency of severe adverse effect between the 2 arms. CONCLUSIONS: Intercalated combination of gefitinib with pemetrexed and cisplatin was well tolerated and improved PFS in never-smoker patients with lung adenocarcinoma.