Approximately three quarters of patients with EGFR mutation-positive NSCLC who progressed following treatment with afatinib had the EGFR T790M mutation.

In this real-world setting, all afatinib-treated patients who developed the EGFR T790M mutation were subsequently treated with osimertinib.

Targeted treatment with afatinib followed by osimertinib results in pronounced responses and provides the potential for long-term chemotherapy-free treatment.