Efgartigimod alfa

How it works

It is an engineered antibody fragment that binds FcRn, blocking the recycling of immunoglobulin G and thereby lowering circulating IgG, including pathogenic autoantibodies.

Prescribing in practice

• Lowering of IgG may increase susceptibility to infection, so monitor for and manage infections during treatment.
• It is administered in treatment cycles guided by clinical response rather than continuously.
• Ensure infections are appropriately managed and immunisation status is considered before starting.

Monitoring

Monitor for signs of infection and assess myasthenia gravis clinical scores to guide the timing of subsequent treatment cycles.

Counselling the patient

• Report symptoms of infection such as fever, cough or urinary symptoms promptly.
• Treatment is given in cycles; the team will determine when the next cycle is needed.
• Keep vaccinations up to date as advised before treatment.

Evidence & guidelines

Efficacy in anti-acetylcholine receptor antibody positive generalised myasthenia gravis was demonstrated in the randomised placebo-controlled ADAPT trial.