Optimizing Treatment Strategies for Egfr -Mutated Non-Small-Cell Lung Cancer Treated with Osimertinib: Real-World Outcomes and Insights.

Background: Osimertinib, a third-generation EGFR tyrosine kinase inhibitor (TKI), demonstrated superior efficacy over first-generation TKIs in the FLAURA trial, resulting in its approval as first-line therapy for metastatic non-small-cell lung cancer (NSCLC). However, the real-world application of these trial results requires an evaluation of sequential therapeutic strategies. Methods: This retrospective, non-interventional study utilized data from the Epidemiological Strategy and Medical Economics (ESME) platform, which includes information on patients treated for lung cancer since 2015. Out of 39,974 patients in the database, 624 patients with EGFR -mutant advanced NSCLC treated with osimertinib as first-line (L1, n = 198) or second-line (L2, n = 426) treatment after first- or second-generation TKIs (n = 1262) were identified. Patient demographics, disease characteristics, treatment strategies, and disease progression were examined. Survival analyses were performed using Kaplan-Meier estimates and Cox proportional-hazards models. Results: In the study population (n = 624), 73.4% were female, with a median age of 70 years (range 28-93). Brain metastases at the start of osimertinib treatment were observed in 282 patients. ECOG PS-2 was reported in 29.4% of patients. The T790M mutation in exon 20 was identified in 257/426 patients (60.3%) receiving osimertinib in L2. Median progression-free survival (PFS) was 12.4 months (95% CI [10.7-14.7]) for L1 and 7.4 months (95% CI [6.2-8.7]) for L2. Median overall survival (OS) from advanced diagnosis was 28.5 months (95% CI [26.3-38.7]) for osimertinib L1 and 29.9 months (95% CI [28.6-31.8]) for osimertinib L2 (HR = 0.93; 95% CI [0.75-1.16]; p = 0.50). For L1, median OS was 27.1 months (95% CI [22.0-30.2]) for patients with cerebral metastases and 38.7 months (95% CI [26.3-52.8]) for those without (HR = 0.73; 95% CI [0.48-1.11]; p = 0.15). Discussion: Patients in the real-world ESME database exhibited a poorer prognosis compared to those in the FLAURA trial. The presence of cerebral metastases at diagnosis worsens the prognosis.