Ivosidenib

How it works

It inhibits the mutant IDH1 enzyme, lowering the oncometabolite 2-hydroxyglutarate and promoting differentiation of leukaemic blasts.

Prescribing in practice

• Differentiation syndrome can occur and may be life-threatening, so recognise features such as fever, dyspnoea and fluid retention early and treat promptly with corticosteroids.
• QT-interval prolongation can occur, so monitor the ECG and electrolytes and review concomitant QT-prolonging or CYP3A-interacting medicines.
• Treatment is guided by confirmation of an IDH1 mutation by a validated test before initiation.

Monitoring

Monitor for differentiation syndrome, perform regular ECGs with electrolyte checks, and follow full blood count during treatment.

Counselling the patient

• Report fever, breathlessness, rapid weight gain or swelling promptly as these may signal a serious reaction.
• Attend for heart tracing and blood tests as scheduled.
• Tell your team about all other medicines, including over-the-counter products.

Evidence & guidelines

Ivosidenib received approval for IDH1-mutated acute myeloid leukaemia on the basis of registrational trials demonstrating remission with mutant IDH1 inhibition.