Real-world outcomes of atypical EGFR-mutated metastatic non-small cell lung cancer (mNSCLC) treated with osimertinib (osi) vs. Afatinib or erlotinib

Highlights•Atypical EGFR mutations in mNSCLC showed worse survival vs. classical mutations (L858R 6 %), Exon 20 (N=11; 3 %), L861Q (N=7; 2 %), S768I (N=4; 1 %), C797S (N=1; 0.3 %); 6 patients had compound mutations. Patients with classical mutations (CMs) vs AMs had similar baseline demographic and disease characteristics and usage of TKIs (p = 0.124). Among AM patients, osi yielded superior mPFS (22 m) vs afatinib (12 m; p = 0.005) or erlotinib (9 m; p = 0.001). mOS was likewise superior for osi (32 m) vs afatinib (21 m; p = 0.032) or erlotinib (17 m; p = 0.011). Dose-reduction rates due to AEs were lower for osi (19 %) vs afatinib (24 %; p = 0.003) or erlotinib (23 %; p = 0.002). Discontinuation rates due to AEs were lower for osi vs afatinib (1 % vs 2 %; p < 0.001) or erlotinib (2 %; p = 0.004).ConclusionsIn a large real-world analysis, osi demonstrated superior progression-free and overall survival and improved tolerability compared to afatinib or erlotinib for atypical EGFR-mutated mNSCLC.