Efficacy of afatinib in the clinical practice: First results of the GIDEON trial: A prospective non-interventional study (NIS) in EGFR mutated NSCLC in Germany

Abstract

Background: Afatinib is an irreversible ErbB family blocker, which is approved as monotherapy for the treatment of advanced non-small cell lung cancer (NSCLC) patients with activating EGFR mutations. Here we report the first interim analysis of the NIS GIDEON, which was initiated to investigate the efficacy and tolerability of Afatinib in first line treatment in the daily clinical routine in Germany. Methods: EGFR-mutated NSCLC patients were treated with Afatinib according to label until progression, death or discontinuation due to patients' or physicians' decision. Efficacy (objective response rate, ORR; disease control rate, DCR and progression-free survival, PFS) was prospectively assessed by investigators and additional data about tolerability under everyday treatment conditions were documented. Results: A total of 151 pat. were enrolled in the study and received Afatinib treatment. EGFR mutations comprised exon 19 deletions (Del19, 56.6%), L858R point mutations (21.9%) and uncommonmutations (18.5%). Median age was 67 years (38-89) with 91 Pat.≥65 years (60.3%). Pat. started treatment on 40mg/d (72.8%) Afatinib or<40mg/d (25.8%). Dose reductions during the course of therapy were frequent, 61.8%with 40mg/d starting dose and 53.8% with<40mg/d.ORR for the total treated population was 73% with aDCR of 90 %.ORRwas similar according to different subgroups, e.g.mutation type and age.mPFS at the time of analysis was 12.9Mon. and in the group of pat.≥65 years 13.7 Mon. OS date are not mature yet. Themost frequent documented AEs were diarrhea and rash/acne, with 11.6%of pat. discontinued treatment due to drug related AEs. Conclusions: Afatinib is a standard therapy for patients with activating EGFR mutations in Germany. The first results of this prospective NIS confirm the robust clinical data for Afatinib in the clinical routine setting, especially in the elderly population, which is underrepresented in clinical trials. A starting dose of<40 mg Afatinib in selected pat. does not seem to be inferior in terms of efficacy.