Treatment Patterns in Patients with Locally Advanced or Metastatic Non-Small-Cell Lung Cancer Treated with Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitors: Analysis of US Insurance Claims Databases

Background Most patients with epidermal growth factor receptor mutation-positive (EGFRm) non-small-cell lung cancer (NSCLC) acquire resistance to first-line (1L) first- or second-generation (1G/2G) EGFR-TKIs; therefore, it is important to optimize 1L treatment to improve patient outcomes. Objective To retrospectively examine treatment patterns in locally advanced/metastatic NSCLC using MarketScan ® Commercial and Medicare Supplemental Databases (all US census regions). Patients and methods Adults with a lung cancer diagnosis code between 1 January 2015–31 March 2018 were analyzed from diagnosis (index) through a variable-length follow-up. Patients had ≥ 1 pharmacy claim for 1G/2G EGFR-TKIs on or within 60 days post-index. Data were stratified by presence or absence of central nervous system (CNS) metastases (30 days pre-index through study end). Results 578 patients were included (median age 63 years, 64% female). Median follow-up was 13.5 months. The most frequently prescribed 1L EGFR-TKI was erlotinib (414/578, 72%). Median time to 1L treatment discontinuation was 8.2 (95% confidence interval (CI) 6.9, 9.0) months in patients diagnosed with CNS metastases at any time, and 7.7 (95% CI 6.9, 8.9) months in patients without CNS metastases. 270/578 patients (47%) discontinued 1L EGFR-TKIs; 209/270 (77%) initiated second-line (2L) therapy, most frequently osimertinib (96/209, 46%). Conclusions In an analysis of US claims data, nearly half of patients discontinued 1L EGFR-TKIs, and 46% who initiated 2L received osimertinib. As nearly a quarter of patients who discontinued 1L EGFR-TKIs did not receive 2L treatment, this study highlights the need for optimal 1L treatment in EGFRm locally advanced/metastatic NSCLC.