Ismonib

Indications

Osimertinib is a targeted cancer medicine for non-small cell lung cancer (NSCLC) whose cancer cells carry certain changes (mutations) in the EGFR gene, confirmed by a laboratory test. It is used:

• after surgery for early lung cancer, to lower the chance of it coming back;
• as first treatment for advanced or spread (metastatic) lung cancer with EGFR mutations, alone or with chemotherapy;
• when the cancer has grown during treatment with another EGFR medicine and has a change called T790M.

How It Works

Osimertinib is an EGFR tyrosine kinase inhibitor. In some lung cancers a faulty EGFR protein keeps telling the cancer cells to grow. Osimertinib blocks this faulty protein, which slows or stops the growth of the cancer.

Dosage and Administration

Only as prescribed by the cancer specialist. The usual adult dose is one 80 mg tablet once a day, at about the same time each day, with or without food. The specialist may lower the dose or pause treatment if side effects occur.

If the tablet cannot be swallowed, it can be placed in about 50 ml of plain (not fizzy) water, stirred until it breaks up and drunk straight away; rinse the glass with more water and drink that too.

If a dose is missed, take it unless the next dose is due within 12 hours; do not take two doses together. Children: not for use.

Interactions

Medicines that speed up its breakdown, such as Rifampicin, Carbamazepine, Phenytoin and the herbal remedy St John's wort, can make Osimertinib much less effective and should be avoided. Care is needed with other medicines that affect the heart rhythm. Tell your doctor about all medicines, vitamins and herbal products you take.

Contraindications

• Allergy to Osimertinib or any ingredient of the tablet
• Use together with St John's wort
• Pregnancy and breastfeeding

Side Effects

Common: diarrhoea, rash, acne-like spots, dry or itchy skin, sore or infected skin around the nails, mouth sores, reduced appetite, tiredness and low blood cell counts.

Less common but serious: inflammation of the lungs, changes in heart rhythm (QT prolongation), weakening of the heart muscle, and eye inflammation.

Get medical help at once for new or worse cough, breathlessness or fever; a fast, pounding or irregular heartbeat or fainting; swelling of the legs with breathlessness; a painful red eye or sudden change in vision; or blistering, peeling skin.

Pregnancy and Lactation

Osimertinib can harm an unborn baby. Women who could become pregnant should use reliable contraception during treatment and for at least 2 months after the last dose; men should use condoms during treatment and for at least 4 months after. Do not breastfeed during treatment and for 2 weeks after the last dose.

Precautions and Warnings

• Your doctor will arrange blood tests, and may check your heart (ECG and heart scan), especially if you have heart problems or low potassium or magnesium.
• Report any breathing problems early.
• Tiredness can affect driving or using machines.

Overdose

If too many tablets are taken, contact the doctor or go to hospital. There is no specific antidote; treatment is supportive with close monitoring.

Therapeutic Class

Targeted anticancer medicine (EGFR tyrosine kinase inhibitor).

Storage

Store below 30°C in a dry place, away from light and out of the reach of children.