Retrospective Analysis of Real-World Management of EGFR -Mutated Advanced NSCLC, After First-Line EGFR-TKI Treatment: US Treatment Patterns, Attrition, and Survival Data

Background and Objectives Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are standard-of-care first-line (1L) treatment for EGFR mutation-positive advanced/metastatic non-small cell lung cancer. In 2015, osimertinib, a third-generation EGFR-TKI, received US accelerated approval for second-line (2L) EGFR T790M-positive non-small cell lung cancer treatment. The objective of this US study was to characterize treatment patterns, attrition, and survival in EGFR mutation-positive non-small cell lung cancer, after 1L first-/second-generation EGFR-TKI treatment. Methods We retrospectively analyzed 1029 patients diagnosed with stage IIIB/IV non-small cell lung cancer from 1 January, 2011 to 31 December, 2018 using the US electronic medical record CancerLinQ Discovery ® database. Demographic/disease characteristics, EGFR mutations, treatments, and death dates were collected. Results From 1 January, 2011 to 31 December, 2014 (< 2015 cohort), 519 patients received 1L EGFR-TKIs and 510 between 1 January, 2015 and 31 December, 2018 (≥ 2015 cohort). Median follow-up from advanced diagnosis was 19.8 months (interquartile range: 9.9–33.4 months). Twenty-eight percent of patients (288/1029) died without receiving 2L, and 52% (539/1029) initiated 2L with 35% (186/539) receiving osimertinib; in the < 2015 and ≥ 2015 cohorts, the same proportion initiated 2L (52%; 272/519 vs 267/510, respectively). Median overall survival from advanced diagnosis for patients initially diagnosed with stage I–IIIA disease was 43.3 months (95% confidence interval 30.9–73.7), vs 26.4 months (95% confidence interval 24.4–28.1) for stage IIIB–IV; all-cause mortality hazard ratio: 1.56 (95% confidence interval 1.2–2.0; p = 0.001). Conclusions We identified disease stage, performance status, and central nervous system metastasis as survival predictors, highlighting the importance of optimal 1L treatment selection. Over a quarter of patients died before initiating 2L; half progressed after 1L and received 2L, of whom a third received 2L osimertinib.