Aim: Osimertinib is a third-generation, irreversible, oral EGFR tyrosine kinase inhibitor. We report real-world effectiveness and safety data. Patients & methods: EGFR T790M positive advanced non-small-cell lung cancer adults, who received ≥1 prior EGFR tyrosine kinase inhibitor, received osimertinib 80 mg daily. Primary effectiveness outcome: overall survival. Secondary effectiveness outcomes included: investigator-assessed clinical response, progression-free survival, time-to-treatment discontinuation. Results: At data cutoff, 3015 patients had enrolled: 57.1% had investigator-assessed response (95% CI: 55.2–58.9). Median progression-free survival: 11.1 months (95% CI: 11.0–12.0) and median time-to-treatment discontinuation: 13.5 months (95% CI: 12.6–13.9). Interstitial lung disease/pneumonitis-like events reported in 28 (1%) patients. Conclusion: Osimertinib demonstrated clinical effectiveness similar to efficacy observed in the clinical trial program with no new safety signals.