Osimertinib, sold under the brand name Tagrisso,[6] is a medication used to treat non-small-cell lung carcinomas with specific mutations.

[4][11] The T790M mutation may be de novo or acquired following first-line treatment with other EGFR tyrosine kinase inhibitors, such as gefitinib, erlotinib, and afatinib.

[4] The Food and Drug Administration (FDA) has approved multiple tests, including FoundationOne CDx for this purpose.

[18] In September 2024, the FDA approved osimertinib for adults with locally advanced, unresectable (stage III) non-small cell lung cancer (NSCLC) whose disease has not progressed during or following concurrent or sequential platinum-based chemoradiation therapy and whose tumors have EGFR exon 19 deletions or exon 21 L858R mutations, as detected by an FDA-approved test.

[20] Common (between 1% and 10% of clinical trial subjects) adverse effects include interstitial lung disease.

[15] The application was granted priority review, fast track, breakthrough therapy, and orphan drug designations.