osimertinib mesylate at a glance
Medicine class
EGFR tyrosine kinase inhibitor and targeted anti-cancer treatment
Cancer type
EGFR-mutated non-small-cell lung cancer in adults
Administration
Oral film-coated tablet that may be taken with or without food
Before treatment
An appropriate validated EGFR test is required
What is osimertinib mesylate used for?
Licensed uses are restricted to adults with eligible EGFR-mutated non-small-cell lung cancer.
Adjuvant treatment after complete resection of stage IB–IIIA disease with an EGFR exon 19 deletion or exon 21 L858R substitution mutation.
Locally advanced, unresectable stage III disease with one of these mutations when cancer has not progressed during or after platinum-based chemoradiotherapy.
First-line monotherapy for locally advanced or metastatic disease with an activating EGFR mutation.
Locally advanced or metastatic EGFR T790M mutation-positive disease.
First-line treatment with pemetrexed and platinum-based chemotherapy for advanced disease with an EGFR exon 19 deletion or exon 21 L858R substitution mutation.
How does osimertinib mesylate work?
Osimertinib binds irreversibly to certain mutated forms of epidermal growth factor receptor, including sensitising EGFR mutations and T790M. Blocking this growth signal can slow cancer-cell growth and may reduce the chance of recurrence after surgery.
osimertinib mesylate preparations and strengths
Tablet
Route: Oral
Strengths: 40 mg, 80 mg
How to take osimertinib mesylate
Follow the oncology team’s prescription. The tablet can be taken with or without food.
Swallow the tablet whole with water; do not crush, split or chew it.
If swallowing is difficult, place the tablet in still water without crushing, stir until dispersed, drink immediately, then rinse the glass with more water and drink the rinse.
Only still water should be used for dispersion. Administration through a nasogastric tube requires the product-specific procedure.
osimertinib mesylate side effects
Common or expected effects
- Diarrhoea
- Rash, itching or dry skin
- Pain, inflammation or other changes around the nails
- Sore mouth or mouth ulcers
- Reduced appetite
- Reduced white blood-cell or platelet counts
- Hives
- Mild hair thinning or nosebleeds
Get urgent medical advice
- New or worsening breathlessness, cough or fever, which may indicate pneumonitis or interstitial lung disease
- Fast or irregular heartbeat, chest discomfort, dizziness or fainting
- Blistering, peeling skin or sores affecting the mouth, eyes or genitals
- Persistent fever, pallor, infection, unusual bruising or bleeding, which may indicate aplastic anaemia
- Eye pain, redness, light sensitivity or vision changes
- Breathlessness, tiredness and ankle swelling suggesting impaired cardiac function
osimertinib mesylate in pregnancy
Human pregnancy information is limited, and animal findings and the medicine’s mechanism indicate potential fetal harm. It should generally be avoided during pregnancy unless specialist assessment concludes that treatment is clinically required. Discuss pregnancy plans, contraception and any suspected pregnancy promptly with the oncology team.
osimertinib mesylate while breastfeeding
It is unknown whether osimertinib enters human milk, and harm to a breastfed child cannot be excluded. Breastfeeding should be discontinued during treatment; discuss feeding options with the oncology and maternity teams.
osimertinib mesylate interactions
Check prescription, non-prescription and herbal products before treatment and whenever medicines change.
St John’s wort
Must not be used because it can substantially reduce osimertinib exposure.
Strong CYP3A inducers, including rifampicin, carbamazepine and phenytoin
May reduce osimertinib exposure and should generally be avoided.
Moderate CYP3A inducers, including bosentan, efavirenz, etravirine and modafinil
May reduce osimertinib exposure and require careful specialist review.
Common questions about osimertinib mesylate
Answers are fully visible for fast scanning and source review.
Why is an EGFR test needed before osimertinib mesylate?
Osimertinib targets particular altered forms of EGFR, so a validated test establishes whether the tumour has a mutation covered by the licensed indication.
Can osimertinib mesylate be taken with food?
Yes. Food does not have a clinically meaningful effect on its absorption.
Can osimertinib mesylate tablets be crushed or split?
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.