Objectives: Central nervous system (CNS) metastases are very common in patients with non-small-cell lung cancer (NSCLC). We aimed to explore the clinical impact of osimertinib, a third-generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), on CNS metastases in patients with advanced NSCLC in real-world setting.
Methods: Patients with advanced NSCLC who received osimertinib after progression of early-generation EGFR-TKIs and CNS metastases on baseline brain scan were retrospectively collected. Primary outcomes were disease control rate (DCR) and progression-free survival (PFS), and secondary objectives were objective response rate (ORR), time to tumor response, median best percentage change from baseline in CNS target lesion (TL) size and safety.
Results: Between Apr 1, 2017, and Dec 30, 2017, 22 patients met selection criteria, 15 with ≥ 1 measurable CNS lesion (RECIST 1.1) were included in CNS evaluable for response (cEFR) set. Among the 22 patients, ORR and DCR were 40.9% and 86.4%, respectively, with median PFS of 8.5 months (95% CI 4.1, 13.0). Median intracranial PFS was not reached. Of 15 patients in cEFR set, CNS DCR was 80.0% with complete response reported in 3 patients (20.0%). Median best percentage change from baseline in CNS TL size was - 40% (range - 100 to + 60%) and median time to CNS tumor response was 1.3 months. CNS ORR was 53.3%. The safety profile was acceptable and no new unexpected findings were found.
Conclusion: This real-world analysis further confirmed that osimertinib indeed demonstrated clinically meaningful efficacy against CNS metastases in Chinese patients with advanced NSCLC.
Keywords: Brain metastases; Central nervous system; Efficacy; Non-small cell lung cancer; Osimertinib.