Efficacy and safety data of osimertinib in elderly patients with NSCLC who harbor the EGFR T790M mutation after failure of initial EGFR-TKI treatment

Background/Aim: The aim of this study was to evaluate the safety and efficacy of osimertinib for elderly patients, since the data remain limited. Patients and Methods: A total of 77 patients with advanced non-small cell lung cancer (NSCLC) harboring the epidermal growth factor receptor (EGFR) T790M mutation and treated with osimertinib were reviewed. Efficacy and safety indicators, such as EGFR-tyrosine kinase inhibitor (TKI)-related adverse events (AEs) and osimertinib-associated hematotoxicity, were evaluated in elderly patients (elderly group, EG; age, ≥75 years) by comparing them with younger patients (non-EG; aged <75 years). The frequency of AEs associated with osimertinib was compared with the initial EGFR-TKI treatment before osimertinib administration in the same patient cohort. Results: Of the total 77 patients, 18 (23%) were assigned to the EG, whereas 59 (77%) were assigned to the non-EG. There were no significant differences in overall response rate and progression-free survival between the two groups. Regarding the safety of osimertinib, the EG had significantly more grade ≥2 paronychia than the non-EG (16.6% vs. 1.6%, p=0.04). Additionally, the maximum grade of EGFR-TKI-related AEs associated with osimertinib in the EG was significantly lower than that of the initial EGFR-TKI treatment (p=0.03). Conclusion: Osimertinib is a safe and effective treatment option for elderly patients with advanced NSCLC who harbor the EGFR mutation.