Data from real world to evaluate the efficacy of osimertinib in non-small cell lung cancer patients with central nervous system metastasis

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.