Real-World Patient Characteristics, Treatment Patterns, and Mutation Testing Patterns Among US Patients with Advanced Non-Small Cell Lung Cancer Harboring EGFR Mutations.

introductionApproximately 15% of patients with non-small cell lung cancer (NSCLC) harbor an epidermal growth factor receptor mutation (EGFRm). Mutation testing (including EGFRm) is recommended for patients with advanced NSCLC (aNSCLC) prior to initiating first-line therapy (L1) or after progression on targeted therapy. To elucidate current and future unmet needs, the present study characterized real-world EGFR testing patterns and treatment patterns in patients with aNSCLC.

methodsThis retrospective observational cohort study evaluated newly diagnosed adult patients with aNSCLC (stage IIIB or higher) from the Flatiron Health database. Eligible patients received at least L1 during 2015-2020 (testing cohorts) or 2011-2020 (treatment cohorts). Eligible patients for the treatment cohorts had an EGFR mutation.

resultsThe testing cohort included 22,726 patients, 75.5% had at least one EGFR test and 15.2% of those tested were positive for EGFR mutation. From 2015 to 2020, the median time from sample collection to test results decreased substantially while the proportion of NGS EGFR tests and use of plasma samples increased. The treatment cohort included 3701 patients (95% common mutations [cEGFR], 5.0% exon 20 insertions [ex20ins]). Three or more lines of therapy (LOTs) were observed in approximately 30% of patients. For L1, most cEGFR patients received EGFR tyrosine kinase inhibitors (EGFR-TKI, 68.1%) or platinum-based chemotherapy (PBC, 24.8%); most ex20ins patients received PBC (66.1%) or EGFR-TKI (17.5%). The most common L2 was EGFR-TKI (54.1%) or PBC (22.8%) for cEGFR and immunotherapy (25.9%) or PBC (25.9%) for ex20ins. No predominant L3 was evident in either group.

conclusionThis real-world study, among the largest analyses of testing patterns for patients with aNSCLC, demonstrates a comprehensive view of treatment patterns for patients with EGFR mutations, including ex20ins. Despite recent improvement, increased use of EGFR testing, including advanced methods, is needed to optimize treatment pathways and outcomes. Additionally, the lack of a predominant therapy in later lines indicates a need for new therapies.