Key takeaways
- Osimertinib (brand name Tagrisso) is a once-daily tablet for non-small cell lung cancer (NSCLC) whose tumours carry certain EGFR gene changes. A test must confirm the change first.
- The US label (revised September 2026) covers use after surgery, after chemoradiation for stage III disease, as a first treatment for advanced disease (alone or with chemotherapy), and after other EGFR-targeted drugs stop working in tumours with a T790M change.
- In the FLAURA trial, the median time before the cancer progressed was 18.9 months with osimertinib, compared with 10.2 months with gefitinib or erlotinib.
- Osimertinib is prescription-only. Serious risks include lung inflammation and heart problems, so treatment needs close monitoring by an oncologist.
Osimertinib uses are limited to lung cancers with specific EGFR mutations, and the medicine is suitable only when a test confirms one. This guide explains what osimertinib (Tagrisso) is, which patients the US label covers, what the main trials found, what is in the tablets, and which risks to discuss with an oncologist.
What is osimertinib and how does it work?
Osimertinib is a kinase inhibitor, a type of targeted cancer medicine. It blocks the epidermal growth factor receptor (EGFR), a protein on the surface of cells that can signal them to grow. In some lung cancers, a change in the EGFR gene keeps that signal switched on. Osimertinib attaches to certain mutant forms of EGFR (known as exon 19 deletions, L858R and T790M) and blocks them. It binds these mutant forms at lower concentrations than normal EGFR, which is why it is called a “targeted” medicine.
It is taken by mouth as a tablet. It does not work for every lung cancer, only for tumours with the EGFR changes named on its label.
What are the osimertinib uses?
The US label approves osimertinib for adults with NSCLC in five situations. In every case, an FDA-approved test must find the required EGFR change.
- After surgery (adjuvant): tumours with an exon 19 deletion or exon 21 L858R mutation, after the tumour has been removed.
- Stage III, unresectable: the same two mutations, when the disease has not progressed during or after platinum-based chemoradiation.
- First treatment, metastatic: the same two mutations in NSCLC that has spread, as a single medicine.
- First treatment with chemotherapy: the same two mutations in locally advanced or metastatic NSCLC, combined with pemetrexed and platinum-based chemotherapy.
- After other EGFR drugs: metastatic NSCLC with a T790M mutation that has progressed on or after an EGFR tyrosine kinase inhibitor (TKI).
Osimertinib is not approved for children, for lung cancers without these EGFR changes, or for other cancer types. Your oncologist decides whether any of these uses fits a patient’s stage, mutation and treatment history.
| At a glance | Detail |
|---|---|
| Medicine | Osimertinib (Tagrisso), a targeted EGFR kinase inhibitor |
| Condition | EGFR mutation-positive non-small cell lung cancer |
| Form and strengths | Tablets, 40 mg and 80 mg, taken by mouth; your oncologist sets the dose |
| Test needed | FDA-approved EGFR test (tumour tissue; plasma for some uses) |
| Common side effects | Diarrhoea, rash, muscle and joint pain, nail changes, dry skin, mouth sores, tiredness, low blood counts |
| Prescription | Prescription-only |
What do the trials show?
The label rests on several randomised phase 3 trials. The numbers below come from the FDA label.
- ADAURA (after surgery, 682 patients): osimertinib versus placebo. The hazard ratio for disease-free survival was 0.20 in the overall group, and for overall survival it was 0.49, meaning fewer deaths over about five years of follow-up.
- LAURA (stage III after chemoradiation, 216 patients): median progression-free survival was 39.1 months with osimertinib versus 5.6 months with placebo.
- FLAURA (first treatment, 556 patients): median progression-free survival was 18.9 versus 10.2 months with gefitinib or erlotinib. Median overall survival was 38.6 versus 31.8 months, though the statistical margin was narrow.
- FLAURA2 (with chemotherapy, 557 patients): adding pemetrexed and platinum chemotherapy to osimertinib raised median progression-free survival to 25.5 months from 16.7 months, and median overall survival to 47.5 months from 37.6 months.
- AURA3 (after other EGFR drugs, 419 patients): median progression-free survival was 10.1 versus 4.4 months with chemotherapy. There was no statistically significant difference in overall survival, and 71% of the chemotherapy group later crossed over to osimertinib.
Progression-free survival is the time until the cancer grows or the patient dies. A hazard ratio below 1 means a lower risk of that event.
What is in Tagrisso tablets?
The active ingredient is osimertinib, supplied as osimertinib mesylate. An 80 mg tablet is equivalent to 95.4 mg of the mesylate salt. The inactive ingredients in the tablet core are mannitol, microcrystalline cellulose, low-substituted hydroxypropyl cellulose and sodium stearyl fumarate. The coating contains polyvinyl alcohol, titanium dioxide, macrogol 3350, talc and iron oxides. Tablets are beige: the 80 mg tablet is oval and marked “AZ 80”, and the 40 mg tablet is round and marked “AZ 40”.
What are the risks and who should be careful?
In a pooled analysis of 1,813 patients taking osimertinib alone, the most common side effects were:
- Diarrhoea (47%)
- Rash (46%)
- Muscle and joint pain (38%)
- Nail changes (34%)
- Dry skin (32%)
- Mouth sores (24%)
- Tiredness (21%)
Low white blood cell, lymphocyte, platelet and red blood cell counts were also very common on blood tests.
The label also lists serious risks:
- Lung inflammation (ILD/pneumonitis): severe and sometimes fatal, in about 4% of patients in the pooled analysis. In LAURA, after chemoradiation, it occurred (including radiation pneumonitis) in 56% of patients on osimertinib and 38% on placebo.
- Heart problems: QTc prolongation (a change in the heart’s electrical rhythm) and cardiomyopathy (weakened heart muscle), which occurred in 3.8% of patients.
- Eye inflammation (keratitis), severe skin reactions, inflammation of skin blood vessels, aplastic anaemia (the bone marrow stops making enough blood cells), and muscle damage with raised CPK (an enzyme).
The label lists no contraindications, but several groups need extra care:
- Patients with heart problems, long QT syndrome or electrolyte problems, and those taking medicines that prolong the QTc interval.
- Patients with a history of lung problems. Earlier trials excluded people with a history of ILD that needed steroids.
- Patients taking strong CYP3A inducers such as rifampin, which can lower osimertinib levels. The label advises avoiding them or changing the dose.
- Pregnancy and breastfeeding. Osimertinib can harm an unborn baby. The label advises contraception during treatment and afterwards (6 weeks for women, 4 months for men with female partners) and advises against breastfeeding during treatment and for 2 weeks after.
Osimertinib is a prescription-only medicine. It must be used under the supervision of a doctor experienced in cancer treatment. Do not start, change or stop it on your own.
There are limits to the evidence:
- Most trial participants were Asian (about 62% to 82%, depending on the trial), so results may not match every population.
- In FLAURA, the overall survival benefit was borderline (hazard ratio 0.80, 95% confidence interval 0.64 to 1.00).
- In FLAURA2, adding chemotherapy brought more blood-count problems and more serious side effects than osimertinib alone.
- Trials excluded some patients, such as those with serious heart rhythm problems or a history of lung disease needing steroids.
Common questions
What is osimertinib used for?
Osimertinib treats non-small cell lung cancer in adults whose tumours have certain EGFR mutations, confirmed by an approved test. It can be used after surgery, after chemoradiation, as a first treatment, or after other EGFR drugs have stopped working.
Is Tagrisso the same as osimertinib?
Yes. Tagrisso is the brand name, and osimertinib is the active ingredient. The tablets come in 40 mg and 80 mg strengths.
What are the most common side effects of osimertinib?
Diarrhoea, rash, muscle and joint pain, nail changes, dry skin, mouth sores and tiredness are the most common. Serious but less common problems include lung inflammation and heart problems, so patients should tell their care team about any new breathing, heart or skin symptoms.
Does osimertinib work for every lung cancer?
No. It is approved only for NSCLC with specific EGFR mutations, and a test must find them first. It is not approved for lung cancers without these changes.
Can I get osimertinib without a prescription?
No. Osimertinib is a prescription-only cancer medicine, and treatment is directed by an oncologist who confirms the mutation test and treatment history.
Sources
- FDA: Tagrisso (osimertinib) prescribing information, revised September 2026: https://www.accessdata.fda.gov/drugsatfda_docs/label/2026/208065s035s036lbl.pdf
- FDA: approval letter for NDA 208065 supplements S-035 and S-036 (2026): https://www.accessdata.fda.gov/drugsatfda_docs/appletter/2026/208065Orig1s035,036ltr.pdf
This article is for educational purposes only and is not medical advice. Always consult your doctor before starting, changing or stopping any medicine.
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