P50.05 Natural History and Real-World Treatment Outcomes for NSCLC Patients with EGFR Exon 20 Insertion Mutation: An IASLC- ASCO CancerLinQ Study

Abstract

Epidermal Growth Factor Receptor (EGFR) exon 20 insertion (ex20ins) mutations account for 2-3% all non-small cell lung cancer (NSCLC) patients. Patients with ex20 ins do not respond to standard EGFR TKI therapy. In this work, we have analyzed the characteristics, treatment patterns and outcomes in this subgroup of NSCLC patients. The ASCO CancerLinQ Discovery dataset was queried to identify patients diagnosed with NSCLC between the years 1995-2018 and with EGFR ex20ins mutations. Data were extracted on patient demographics, tumor characteristics, treatments and outcomes, and compared with Chi-square and ANOVA tests. Kaplan-Meier (KM) curves were generated for comparing overall survival with log-rank tests. All analyses were performed using Python 3.6. A total of 357 patients were eligible. Patient characteristics: median age 68 years, female 53.5%, white race 63% and black race 9%. Approximately 62% had stage 4 disease, and 30% had brain metastasis. 54% of the patients were treated with chemotherapy and 15% with immune check point inhibitors (ICI). In patients with brain metastasis, 16% were treated with ICI, 18% targeted therapy and 59% with chemotherapy. The median survival of the entire group is 23.8 months. Among patients with stage 4 disease: 51% were females, 64% white race, 37% had brain metastasis, 18% were treated with ICI, 14% targeted therapy and 60% treated with chemotherapy. In the analysis of stage 4 patients, the median survival of the group was 16.8 months. Stage 4 patients that received ICI had better survival vs. those who did not (29.1 vs. 14.7 months; p=0.01). Stage 4 patients treated with ICI and chemotherapy had better survival compared to those treated with chemotherapy alone (29.1 vs. 16.5 months, p=0.01). Stage 4 patients treated with targeted therapy had better survival compared to those that did not receive targeted therapy (20.6 vs. 16.1 months; p=0.03). Stage 4 NSCLC patients with EGFR ex20ins mutation had favorable real-world survival when treated with ICI and targeted therapy.