efgartigimod alfa at a glance
Medicine class
Selective immunosuppressant and neonatal Fc receptor inhibitor.
Licensed roles
Add-on treatment for eligible adults with AChR-antibody-positive generalised myasthenia gravis; the subcutaneous product also treats eligible adults with active CIDP after previous corticosteroid or immunoglobulin treatment.
Administration
Given by healthcare-administered intravenous infusion or subcutaneous injection. The injection may sometimes be given at home after training and supervised initiation.
Key precaution
It lowers IgG and may increase susceptibility to infection; review vaccination plans with the clinical team.
What is efgartigimod alfa used for?
The licensed indication depends on the formulation.
Generalised myasthenia gravis: add-on to standard therapy in adults positive for antibodies against the acetylcholine receptor.
Chronic inflammatory demyelinating polyneuropathy: the subcutaneous formulation may be used alone in adults with progressive or relapsing active disease after previous corticosteroid or immunoglobulin treatment.
The intravenous concentrate is licensed for generalised myasthenia gravis, not CIDP.
How does efgartigimod alfa work?
Efgartigimod alfa is an engineered IgG1 Fc fragment that binds the neonatal Fc receptor, FcRn. Blocking this receptor increases removal of IgG, including disease-causing IgG autoantibodies, without directly lowering IgA, IgD, IgE, IgM or albumin.
efgartigimod alfa preparations and strengths
Solution for infusion
Route: Intravenous
Strengths: 20 mg/mL
Injection
Route: Parenteral
Strengths: 1000 mg
How to take efgartigimod alfa
The intravenous concentrate is diluted and given by a healthcare professional. The pre-filled syringe is injected under the skin of the abdomen; rotate injection areas and avoid tender, bruised, red, hard, scarred or mole-covered skin.
Use the subcutaneous product at home only if the clinical team considers this appropriate and you or your caregiver have completed training.
Allow the pre-filled syringe to reach room temperature naturally before use and do not shake it.
Check the solution and packaging as instructed; do not use a damaged syringe or solution with visible particles.
efgartigimod alfa side effects
Common or expected effects
- Upper respiratory tract infection
- Urinary tract infection
- Bronchitis
- Injection-site redness, itching, rash or pain with the subcutaneous formulation
- Headache related to intravenous administration
- Muscle pain
- Nausea
Get urgent medical advice
- Anaphylaxis or another severe hypersensitivity reaction, including facial or throat swelling, severe breathing difficulty, fainting or collapse
- A serious or rapidly worsening infection
efgartigimod alfa in pregnancy
Human pregnancy data are unavailable. Efgartigimod alfa may cross the placenta and could reduce transfer of protective maternal antibodies to the baby, so treatment requires specialist assessment of benefits and risks. The baby’s vaccination plan, particularly for live vaccines, may need specialist review after exposure during pregnancy.
efgartigimod alfa while breastfeeding
It is unknown whether efgartigimod alfa enters human milk or affects a breastfed child or milk production. Discuss breastfeeding and treatment with the specialist team so maternal benefit and possible infant risk can be considered together.
efgartigimod alfa interactions
Formal interaction studies are limited. Tell the specialist team about all medicines, vaccines and antibody-based treatments.
Immunoglobulin products, including intravenous immunoglobulin
Efgartigimod alfa may lower their circulating concentrations and potentially reduce their intended effect.
IgG monoclonal antibodies and other Fc-containing antibody treatments
Their concentrations and effectiveness may be reduced, requiring treatment planning and monitoring of response.
Common questions about efgartigimod alfa
Answers are fully visible for fast scanning and source review.
What is efgartigimod alfa used for?
It treats selected adults with AChR-antibody-positive generalised myasthenia gravis alongside standard therapy. The subcutaneous formulation is also licensed for selected adults with active CIDP after previous corticosteroid or immunoglobulin treatment.
Is efgartigimod alfa an immunosuppressant?
Yes. It is classed as a selective immunosuppressant because it lowers circulating IgG antibodies by blocking FcRn.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.