Analysis of the Clinical Effect of Osimertinib on 90 Cases with Advanced Lung Adenocarcinoma

Background: Primary or secondary drug resistance of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKI) is a new challenge in the treatment of advanced non-small cell lung cancer (NSCLC). Osimertinib is a third-generation EGFR-TKI, and its efficacy and safety in NSCLC patients with first generation EGFR-TKI resistance, especially lung adenocarcinoma, are not yet clear. The purpose of this study was to observe the efficacy and adverse reactions of osimertinib in the treatment of patients with advanced lung adenocarcinoma. Methods: From January 2017 to December 2018, 90 patients with advanced (stage IV) lung adenocarcinoma were diagnosed in Shanghai Chest Hospital. The disease of these patients (94.4%) progressed after first-line EGFR-TKI treatment, and 43.3% of patients received third-line or beyond third line treatment. The efficacy and adverse reactions of osimertinib treatment were observed. Results: Among 90 patients with advanced lung adenocarcinoma, 57 (63.3%) achieved partial response (PR), 27 (30.0%) had stable disease (SD), and 6 (6.7%) had progressive disease (PD). The objective response rate (ORR) was 63.3%, and the disease control rate (DCR) was 93.3%. The median progression-free time (mPFS) was 10.41 months (95% CI: 8.91-11.91 months), and the median overall survival (mOS) was 31.37 months (95% CI: 26.37-36.37 months). The incidence of adverse events of degree 3 and above was 7.78%. The main adverse events were diarrhea (28.9%) and rash (24.4%). After symptomatic treatment, the incidence of adverse events was significantly reduced. Conclusions: Osimertinib has a definite curative effect in the treatment of patients with advanced lung adenocarcinoma, and the incidence of adverse reactions is low.