Biomarker Testing Patterns in Patients with Stage IV Non-Small Cell Lung Cancer (NSCLC) in U.S. Community-Based Oncology Practice Setting.

300 Background: This study evaluated rates of biomarker testing for patients with stage IV non-squamous NSCLC, which is known to have a ̃40% biomarker-positive rate (AMP, 2020), in a community-based oncology practice setting in the United States (US). Methods: A retrospective study was performed using data from a US electronic medical record database of patients aged ≥18 years with an initial diagnosis (index dx) of stage IV non-squamous NSCLC between Jan 1, 2015 and Dec 31, 2019. Unstructured data on molecular biomarker testing (single-gene and next-generation sequencing [NGS]-based) were abstracted from patient charts utilizing Natural Language Processing for EGFR mutation, ALK rearrangement, BRAF mutation, ROS1 rearrangement, MET exon14 mutation, RET fusion, NTRK fusion, and PD-L1 expression. Systemic therapy was obtained from structured data. Data were summarized using descriptive statistics. This study received a waiver of consent from Advarra IRB. Results: Of 646 patients identified in the database, 500 met all inclusion criteria and are included in this analysis. The majority (73.8%) were diagnosed in 2018 (n = 162; 32.4%) and 2019 (n = 207; 41.4%). Mean age (SD) was 70.0 (10.1) years, with 53.2% female. A total of 447 (89.4%) were tested for at least one biomarker after index diagnosis of which 81.2% (n = 406) had at least one single-gene test; 54.8% (n = 274) had an NGS test and 66.8% were tested for PD-L1. Single-gene or NGS-based testing was > 85% of patients across all index years. The use of NGS-based tests ranged from 35.0% among patients whose first diagnosis was in 2015 to 59.4% in 2019. Overall, 85.4% (n = 427) of the cohort received first-line treatment with chemotherapy (53.6%), immunotherapy (48.2%), or targeted therapy (14.2%). Among patients who received biomarker tests, 15.4% received targeted treatment and 49.7% received immunotherapy treatment, including checkpoint inhibitors, during first-line treatment. Conclusions: NGS testing utilization increased during the study period and by 2019, 59% of patients received NGS-based testing. Opportunities persist for practices to improve testing and achieve guideline recommendations. PD-L1 biomarker testing was performed amongst the highest proportion of patients in this study and nearly 50% of all patients received immunotherapy, including checkpoint inhibitors. Targeted therapy was used in 14.2% of this population, suggesting that patients with actionable biomarkers may not be receiving targeted treatment for their disease, potentially due to gaps in testing among patients in this dataset.