Real-Life Efficacy of Osimertinib in Pretreated Octogenarian Patients with T790M-Mutated Advanced Non-small Cell Lung Cancer

Background The resistance mutation T790M is reported in 50-60% of patients pretreated with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). Osimertinib has been approved in these patients, but data in octogenarians remain rare. Objective The objective of this retrospective analysis was to evaluate in real life the efficacy of osimertinib in a population of octogenarian patients. Methods This retrospective multicentric study included pretreated octogenarian patients with EGFR T790M-mutated advanced non-small cell lung cancer (NSCLC) in the setting of the French early access program for osimertinib. The primary endpoints were progression-free survival (PFS) and overall survival (OS) from osimertinib initiation. Results In total, 43 patients were included (mean age 84.6 years; women 90.7%: adenocarcinoma 100%; never smokers 90.5%; at osimertinib initiation: performance status >= 2, 42.4%; stage 4, 93.0%; brain metastases 16.3%). Patients received a median of two lines of treatment before osimertinib initiation, and all received first- or second-generation EGFR TKIs before osimertinib (first line in 79.1%). Osimertinib was used as a second-line treatment in 41.9% of cases and third line or more in 58.1%. Median PFS was 17.5 (95% confidence interval [CI] 12.2-19.0) months for the entire population: 20.6 (95% CI 18.8-not reached) months in patients with brain metastases and 16.7 (95% CI 10.4-18.9) months in patients without (p = 0.1). There was no significant difference for osimertinib treatment as second or third line or more (17.1 vs. 18.6months, respectively). OS was 22.8 (95% CI 15.7-not reached) months from osimertinib initiation. Conclusion The efficacy of osimertinib as second-line treatment or more in octogenarian pretreated patients with EGFR T790M-mutated advanced NSCLC in a real-life setting was similar to that in randomized controlled trials.