European and US Real-World Treatment Patterns in Patients with Epidermal Growth Factor Receptor Mutation-Positive Non-Small Cell Lung Cancer: A Retrospective Medical Record Review

BACKGROUND: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are the preferred first-line (1L) therapy for EGFR mutation-positive (EGFRm) advanced/metastatic non-small cell lung cancer (NSCLC). OBJECTIVE: Our objective was to describe real-world treatment patterns and T790M testing practices in patients with 1L disease progression (Europe/USA) following treatment with first- or second-generation EGFR-TKIs. METHODS: This was a retrospective, non-interventional medical record review of patients with EGFRm locally advanced/metastatic NSCLC from routine clinical practice (EGFR-TKI initiation: 1 January 2015 to 31 December 2017; follow-up: last available medical record). Endpoints were demographic/clinical characteristics, incidence of central nervous system (CNS) metastases/leptomeningeal disease, second-line (2L) treatment, T790M mutation testing, and osimertinib treatment prevalence. RESULTS: Among 469 patients, 73% (n = 341/469) progressed on 1L EGFR-TKI treatment. Of those who progressed, 74% (n = 252/341) were tested for T790M, with 50% (n = 126/252) testing positive; 75% (n = 94/126) of T790M-positive patients received osimertinib (mostly 2L). Of the patients with progression, 24% (n = 83/341) did not receive 2L treatment, and 88% (n = 73/83) of these patients died. At diagnosis of advanced disease, 9% of patients (n = 41) had CNS metastases; at EGFR-TKI initiation, 14% of patients (n = 68) had CNS metastases. Over the study period, 11% of patients (n = 42) developed CNS metastases not detected at NSCLC diagnosis. CONCLUSIONS: Rates of resistance mutation testing and subsequent utilization of recommended 2L therapies could be improved. As more targeted therapies are developed, it will be crucial to improve the molecular testing rates to ensure patients receive appropriate, effective, and timely treatment. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40801-021-00261-8.