Time on Treatment and Survival Outcomes for Patients Treated With First-line Osimertinib vs. Other Tyrosine Kinase Inhibitors, for EGFR Mutation-positive Metastatic Non-small Cell Lung Cancer: Real-world Experience Data

Background/Aim: In this observational study, we analyzed the time on treatment (ToT) and overall survival (OS) of patients with metastatic non-small cell lung cancer (mNSCLC) in a 2.7-million-member public health provider in Israel. Patients and Methods: Newly diagnosed patients with mNSCLC who initiated first-line tyrosine kinase inhibitor (TKI) therapy between Jan 2017-Dec 2020 were identified from the National Cancer Registry and Maccabi Healthcare Services database. Outcomes were assessed at a minimum of 23 months of follow-up (cutoff: 30th November 2022). All analyses compared first-line treatment osimertinib vs. standard TKIs (erlotinib, afatanib or gefitinib). Results: A total of 165 patients (59% female, median age 68 years) were identified, including 58% smokers, 95% with adenocarcinomas, 33% with brain metastases, and 62%/15%/23% with 0-1/2-4/unknown performance status (PS). Of these, 77 (47%) were treated with standard TKI drugs and 88 (53%) with osimertinib as first-line treatment. The median duration of follow-up was 33.6 months (95%CI=29.9-37.3) and 58.5 months (95%CI=52.5-64.4) for patients who received osimertinib and standard TKIs, respectively. The median ToT (in months) was significantly (p<0.0001) longer with osimertinib (17.6; 95%CI=13.71-23.9) vs. standard TKIs (9.40; 95%CI=7.17-12.1). The 24-month survival rate was 58.0% among patients who received osimertinib and 50.6% among those who received standard TKI therapy (p=0.18). From second-line treatment initiation, 43.8% of those who received second-line osimertinib and 17.7% of those that received other second-line treatment were still alive at 24 months. Conclusion: Compared to standard TKIs, first-line osimertinib treatment was associated with a significantly longer ToT, and a longer OS. Our cohort also included patients with PS 2-4 who would not necessarily be included in clinical trials, allowing analysis of a real-world population.