A phase I study investigating resistance mechanisms to the third‐generation EGFR‐TKI abivertinib in patients with acquired EGFR T790M NSCLC identified three patients with concurrent acquired T790M mutation and EGFR amplification following prior treatment with first‐ or second‐generation EGFR‐TKI. Here, EGFR is linked to non-small cell lung carcinoma.