Osimertinib

How it works

It irreversibly inhibits EGFR carrying sensitising mutations and the T790M resistance mutation, blocking downstream signalling that drives tumour cell proliferation and survival.

Prescribing in practice

• Interstitial lung disease or pneumonitis can occur and may be fatal; withhold treatment and investigate promptly if new or worsening respiratory symptoms develop.
• It can prolong the QT interval and affect cardiac function, so baseline and periodic ECG and electrolyte assessment are advised.
• Treatment is initiated and supervised by specialists experienced in cancer therapy, with confirmed EGFR mutation status.

Monitoring

Monitor for respiratory symptoms suggesting pneumonitis, perform periodic ECGs and electrolyte checks, and assess cardiac function during treatment.

Counselling the patient

• Report any new or worsening cough, breathlessness or fever straight away.
• Tell your team about palpitations or fainting and about all other medicines you take.
• Take it at the same time each day and use reliable contraception as advised.

Evidence & guidelines

The FLAURA trial established osimertinib as first-line therapy for EGFR-mutated advanced non-small-cell lung cancer, and it is recommended by NICE.