How it works

Efgartigimod is a new medication for myasthenia gravis that is the first of its kind. It is an antagonist of the neonatal Fc receptor, meaning that it binds to this specific receptor. The neonatal Fc receptor is responsible for maintaining IgG (immunoglobulin G) levels inside the body. IgG is the autoantibody that binds to the acetylcholine receptor (AChR) in patients with myasthenia gravis. Efgartigimod, by inhibiting the neonatal Fc receptor, reduces the levels of IgG in the body, resulting in a reduction of blockage for the AChR and an increased likelihood of successful binding to ACh. It is suggested that it may work for all antibody-positive patients, with potential to also work for those who present as antibody-negative (around 10% of those with myasthenia gravis).

Through EAMS, efgartigimod was made available early to patients referred by their neurologist.

As of March 2023, efgartigimod was granted MHRA marketing authorisation, meaning it is now able to be placed on the UK market.

How it is delivered

Currently, efgartigimod is delivered intravenously. This can be carried out at the hospital or arranged to take place at home.

When you have it

Efgartigimod infusions are administered for one hour once weekly for four weeks as one treatment cycle. Patients are monitored for signs and symptoms of hypersensitivity reactions during infusion and for one hour.

Side effects

Common – burning, itching, headache. If these symptoms persist, speak to your doctor.

Adverse – bladder pain, bloody or cloudy urine, cough, difficult, burning, or painful urination, difficulty in moving, fever, frequent urge to urinate, joint pain, lower back or side pain, muscle aches, sore throat, swollen joints. If these symptoms occur, immediately speak to your doctor.

Related UK companies

Argenx (developer) 

Click here to report a side effect to the MHRA.