A real-world study of second or later-line osimertinib in patients with EGFR T790M-positive NSCLC: the final ASTRIS data

Aim: Report the final analysis from ASTRIS, the largest real-world study of second-/later-line osimertinib in advanced/metastatic EGFR T790M non-small-cell lung cancer (NSCLC). Methods: Patients with advanced/metastatic EGFR T790M NSCLC and prior EGFR-TKI treatment, received once-daily osimertinib 80 mg. Primary end point: overall survival (OS); secondary end points: progression-free survival (PFS), time-to-treatment discontinuation (TTD) and response rate. Safety was also recorded. Results: In 3014 patients, median OS: 22.8 months (21.6-23.8), median PFS: 11.1 months (11.0-12.0), median TTD: 13.5 months (12.6-13.9), and response rate: 57.3% (55.5-59.2). All end points reported with 95% CIs. Numerically longer median OS was observed in patients with baseline WHO performance status <2 versus 2 (24.0 vs 11.1 months) and those without versus with brain/leptomeningeal metastases (25.4 vs 18.0 months). No new safety signals were identified. Conclusion: Second-/later-line osimertinib demonstrated real-world clinical benefit and safety in advanced/metastatic EGFR T790M NSCLC. Clinical Trial Registration: NCT02474355 (ClinicalTrials.gov).Osimertinib is a drug that blocks the activity of a protein called EGFR on cancer cells, reducing their growth and spread. ASTRIS is the largest real-world study that evaluated the outcomes with osimertinib treatment for patients with advanced non-small-cell lung cancer (NSCLC), and the EGFR T790M mutation, who had received previous treatment for their cancer. There were 3014 patients included in this study. The main aim of this study was to measure the time at which half of the patients were still alive after starting osimertinib treatment, this was 22.8 months. The study also measured the time at which half of the patients had experienced worsening (progression) of their cancer (11.1 months) and the time when half of the patients had stopped receiving osimertinib treatment (13.5 months). None of the patients experienced any unexpected side effects of the treatment. These data are consistent with those observed in comparable clinical trials with osimertinib, supporting the use of osimertinib treatment for patients with advanced NSCLC and the EGFR T790M mutation after their initial cancer treatment has stopped working.