CP-051 Comparing the efficacy of afatinib versus erlotinib or gefitinib in non-small cell lung cancer patients

BackgroundAfatinib is a second generation irreversible EGFR tyrosine kinase inhibitor (TKI), indicated as firstline therapy in non-small cell lung cancer (NSCLC). There are two other first generation EGFR TKIs indicated in NSCLC treatment, and no direct comparison of them.PurposeTo compare the efficacy of afatinib versus erlotinib or gefitinib in EGFR TKIs naïve patients with NSCLC.Material and methodsThis was an observational retrospective study carried out between January 2015 and April 2016. All patients with NSCLC undergoing firstline treatment with an EGFR TKI were included. Patient data were taken from clinical records. Efficacy endpoints were overall survival (OS), progression free survival (PFS) and response rate, assessed by RECIST criteria.Results46 patients were included. 76% were men, average age was 71 years. 71.8% had an ECOG performance status of 0–1 and 76% were current or past smokers. NSCLC stage was III/IV in 84.4% of patients and histologic type was adenocarcinoma in 37% of patients. 43.5% were treated with erlotinib, 39.9% with gefitinib and 17.4% with afatinib. EGFR status was determined in only 16 patients, being mutated in 7 (4 treated with erlotinib and the other 3 with afatinib). Median OS for afatinib, gefitinib and erlotinib was 5, 14 and 43 months, respectively (HR (95% CI) gefitinib vs afatinib: 0.25 (0.07–0.81); erlotinib vs afatinib: 0.16 (0.05–0.55)). Median PFS was 2 months for afatinib, 8 months for gefitinib and 16 months for erlotinib (HR (95% CI) gefitinib vs afatinib: 0.18 (0.06–0.59); erlotinib vs afatinib: 0.08 (0.02–0.29)). Response rate by group was 37.5%, 61.1% and 80% for afatinib, gefitinib and erlotinib, respectively.ConclusionAccording to the main clinical guidelines, EGFR mutation status should be known before the start of treatment, and EGFR TKIs should only be used in patients with a positive EGFR mutation test. Our study suggests that afatinib is less effective than erlotinib or gefitinib, but our population was small. Further studies with more patients are needed to compare afatinib with the other EGFR TKIs.References and/or acknowledgementsSequist LV, Yang JC-HC-H, Yamamoto N, et al. Phase III study of afatinib or cisplatin plus pemetrexed in patients with metastatic lung adenocarcinoma with EGFR mutations. J Clin Oncol2013;31:1–11.No conflict of interest