P3.02b-088 TKI as First Line Treatment in Advanced Non-Small-Cell Lung Cancer with EGFR Mutations: Topic: EGFR Clinical

Abstract

Erlotinib and gefitinib are reversible, first-generation, single-target tyrosine kinase inhibitors (TKIs) to EGFR/ERBB1 receptor. Testing for epidermal growth factor receptor (EGFR) mutations is recommended in patients with nonsquamous non-small cell lung cancer (NSCLC) or NSCLC not otherwise specified as the mutations are predictive biomarkers of response to EGFR TKI therapy. We aim to assess the real world effectiveness of these agents in the setting of the largest Oncologic Centre in Portugal. Retrospective analysis of a consecutive series of patients with stage IIIB/IV NSCLC, EGFR mutated, treated with erlotinib or gefitinib as first line treatment, since January 2012 at Instituto Português de Oncologia do Porto, Portugal. Descriptive statistics were used to describe demographics. Treatment effectiveness was assessed by overall survival (OS) and progression free survival (PFS) calculated by Kaplan-Meier method and treatment adverse events (AEs). Of 86 patients with stage IIIB/IV NSCLC, EGFR mutated, treated with TKI therapy at our center, 64% were female and the mean age was 65.9 years (range 41-85). The majority of patients were non-smokers (80.2%) and the most frequent histology was adenocarcinoma (97.7%). The most commonly found EGFR mutations were deletions in exon 19 and mutation in exon 21. Fifty-one patients (59.3%) received erlotinib as first line treatment. As of May 2016, 39 patients (45.3%) are still on first line treatment, with a median follow-up time of 11 months. Median OS was 24 months (CI 95%: 16.7 – 31.3). The overall response rate (ORR) in the erlotinib group and gefitinib group was 41.2% and 34.3%, respectively, with no significant difference between groups (p value 0.652). Overall median PFS was 10 months (CI 95%: 7.4 – 12.6), being higher in the erlotinib treatment group (11 versus 7 months). Ten patients in the erlotinib group required dose reductions because of drug related toxic effects, 9 because of rash grade 3 and 1 because of hepatotoxicity. One patient in the gefitinib group suspended treatment because of arthritis. Diarrhea was the second most frequent toxicity related to TKIs (38.4%). Based on our experience, real world effectiveness of erlotinib and gefitinib are similar. Patients treated with gefitinib tend to have less adverse events.