Abstract
INTRODUCTION: EGFR exon 20 insertions (EGFRex20ins) are a diverse set of mutations in NSCLC that are refractory to tyrosine kinase inhibitors. We describe real-world EGFRex20ins detection patterns in patients with advanced NSCLC in the United States. METHODS: Data from 2011 to 2020 were extracted from the Flatiron Health electronic health record-derived deidentified database. RESULTS: Among 67,281 patients with advanced NSCLC and at least two clinic visits, 66.8% were tested for EGFR mutations, of whom 13.9% tested positive. Of these, 4.9% had EGFRex20ins. The median time from NSCLC diagnosis to the first positive EGFRex20ins test result was 23 days, including 9 days of laboratory testing time. The EGFRex20ins were reported in 0.6% to 1.0% of all patients with advanced NSCLC and account for 3.9% to 5.3% of all EGFR mutations. During the study period, reverse transcription-polymerase chain reaction testing rates decreased whereas next-generation sequencing rates increased both in overall and among patients with tumors positive for EGFRex20ins. Tissue was the most common sample type used for EGFR and EGFRexon20ins detection (81.1% and 84.9%, respectively), whereas blood sampling for EGFRexon20ins detection increased from 0% (2011) to 37.2% (2020). For 23.7% of patients with EGFRex20ins, treatment was initiated before receiving the first positive EGFRex20ins test result, with therapies including immuno-oncology agents as the most common treatment type from 2017 to 2020. CONCLUSIONS: EGFR testing and detection of EGFRex20ins in patients with NSCLC have increased slightly over time with the increasing use of next-generation sequencing. The current late-stage development of EGFRex20ins-targeted therapy is driving a need for more efficient testing.