Osimertinib is an irreversible EGFR inhibitor registered for advanced NSCLC patients whose tumors harbor recurrent somatic activating mutations in EGFR (EGFRm<sup>+</sup>) or the frequently occurring EGFR-T790M resistance mutation.
It is approved for first-line treatment of patients with advanced non-small cell lung cancer (NSCLC) whose tumors have EGFR exon 19 deletions or exon 21 L858R mutations, and for patients with T790M-positive advanced NSCLC whose disease has progressed on or after EGFR-TKI therapy.