osimertinib
Tagrisso (osimertinib) is an oral, mutant-selective EGFR inhibitor from AstraZeneca for non-small cell lung cancer carrying activating EGFR mutations. It is used after surgery, after chemoradiation, as first-line therapy for advanced disease, and against the T790M resistance mutation.
This page is based on FDA prescribing information and the EMA medicine record for osimertinib, cross-checked with DailyMed and the National Cancer Institute dictionary; the mechanism is explained in plain language, and analogies are used only where they stay accurate.
How it works
Explains what the medicine does in the body, not dosing, side effects, or safety.
An analogy
Some lung cancers run on a stuck accelerator, a mutant EGFR that keeps telling the cell to grow. First-generation drugs block it until the cancer swaps in a new part, the T790M mutation, that knocks them loose. Osimertinib is shaped for the upgraded engine too: it bolts permanently onto the mutant receptor, including T790M, and shuts the growth signal down while largely sparing the normal version.
In simple terms
Certain lung cancers depend on mutated forms of EGFR, a receptor that tells cells to grow. Osimertinib is taken by mouth and binds irreversibly to these mutant receptors, including the T790M resistance mutation, exon 19 deletions, and L858R. By blocking EGFR signalling it can induce cancer cell death and slow tumour growth. Because it is selective for mutant forms of EGFR over the normal receptor, it tends to spare healthy tissues that rely on ordinary EGFR signalling.
In depth
Osimertinib is a third-generation, orally available, irreversible, mutant-selective EGFR inhibitor. Upon oral administration it covalently binds to and inhibits numerous mutant forms of EGFR, including the secondarily acquired resistance mutation T790M, L858R, and exon 19 deletions, thereby preventing EGFR-mediated signalling that drives tumour cell proliferation and vascularisation. Its selectivity for mutant over wild-type EGFR reduces toxicity relative to non-selective EGFR inhibitors. Tumours are selected for treatment with an FDA-approved or companion test identifying the relevant EGFR mutation.
See it in motion
A schematic animation of the mechanism — simplified for clarity, not drawn to scale.
Osimertinib is shaped for the upgraded engine too
- Some lung cancers run on a stuck accelerator, a mutant EGFR that keeps telling the cell to grow.
- First-generation drugs block it until the cancer swaps in a new part, the T790M mutation, that knocks them loose.
- Osimertinib is taken by mouth and binds irreversibly to these mutant receptors, including the T790M resistance mutation, exon 19 deletions, and L858R.
- Because it is selective for mutant forms of EGFR over the normal receptor, it tends to spare healthy tissues that rely on ordinary EGFR signalling.
Target: Mutant epidermal growth factor receptor (EGFR), including T790M
A receptor tyrosine kinase that drives tumour cell proliferation and blood vessel formation when mutated; the T790M change is the most common reason earlier EGFR drugs stop working.
Approved uses
Approved uses differ by country and change over time. Always follow your local prescribing information.
Approved uses in United States
FDA- As adjuvant therapy after tumor resection in adults with non-small cell lung cancer whose tumors have EGFR exon 19 deletions or exon 21 L858R mutations, as detected by an FDA-approved test
- For the treatment of adults with locally advanced, unresectable (stage III) non-small cell lung cancer 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
- For the first-line treatment of adults with metastatic non-small cell lung cancer whose tumors have EGFR exon 19 deletions or exon 21 L858R mutations
- In combination with pemetrexed and platinum-based chemotherapy, for the first-line treatment of adults with locally advanced or metastatic non-small cell lung cancer whose tumors have EGFR exon 19 deletions or exon 21 L858R mutations
- For the treatment of adults with metastatic EGFR T790M mutation-positive non-small cell lung cancer whose disease has progressed on or after EGFR tyrosine kinase inhibitor therapy
Approved uses in European Union
EMA- As monotherapy, for the adjuvant treatment after complete tumour resection in adults with stage IB-IIIA non-small cell lung cancer whose tumours have EGFR exon 19 deletions or exon 21 (L858R) substitution mutations
- As monotherapy, for the treatment of adults with locally advanced, unresectable non-small cell lung cancer whose tumours have EGFR exon 19 deletions or exon 21 (L858R) substitution mutations and whose disease has not progressed during or following platinum-based chemoradiation therapy
- As monotherapy, for the first-line treatment of adults with locally advanced or metastatic non-small cell lung cancer with activating EGFR mutations
- As monotherapy, for the treatment of adults with locally advanced or metastatic EGFR T790M mutation-positive non-small cell lung cancer
- In combination with pemetrexed and platinum-based chemotherapy, for the first-line treatment of adults with advanced non-small cell lung cancer whose tumours have EGFR exon 19 deletions or exon 21 (L858R) substitution mutations
Official sources
The statements on this page trace back to these records.
- Tagrisso (osimertinib) — Summary of product characteristics and package leaflet, English version
European Medicines Agency
- DailyMed: TAGRISSO (osimertinib) official US label
U.S. National Library of Medicine, DailyMed
- U.S. Food and Drug Administration: osimertinib prescribing information
U.S. Food and Drug Administration
- National Cancer Institute: osimertinib
National Cancer Institute
This page explains how the medicine works — it isn’t the patient leaflet. For anything that applies to you, read the leaflet that came with your medicine or ask your pharmacist.
MedUnfold provides educational content and is not medical advice. Always follow your local prescribing information and healthcare professional.