Vyvgart (efgartigimod alfa)
Also marketed as Vyvgart Hytrulo. An approved treatment for Myasthenia Gravis.
The same compound appears under different names depending on the context. Here is how to identify Efgartigimod alfa wherever you encounter it, plus the key facts at a glance.
- Generic name
- Efgartigimod alfa
- Brand names
- Vyvgart, Vyvgart Hytrulo
- Development code
- ARGX-113
- Drug class
- FcRn inhibitor
- Manufacturer
- argenx
- How it's taken
- Available as a 1-hour IV infusion (Vyvgart, 10 mg/kg) given weekly for 4 weeks per cycle, or a subcutaneous injection (Vyvgart Hytrulo, approved 2023) given weekly for 4 weeks per cycle.
The first FcRn inhibitor approved for generalized myasthenia gravis. Rapidly lowers the harmful antibodies that attack the connection between nerves and muscles, improving strength within weeks. Since May 2026 it is approved for all adults with generalized myasthenia gravis, including people who test negative for AChR, MuSK and LRP4 antibodies, the only targeted MG drug with that approval.
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Where Efgartigimod alfa fits
First FcRn blocker for generalized MG, reducing pathogenic antibodies through a novel mechanism. Available in IV and subcutaneous formulations, offering flexibility in administration.
How Efgartigimod alfa works
In myasthenia gravis, the immune system makes antibodies (IgG) that attack acetylcholine receptors at the neuromuscular junction, causing muscle weakness. Efgartigimod blocks the neonatal Fc receptor (FcRn), which normally recycles IgG antibodies and keeps their levels high. By blocking this recycling, efgartigimod causes a rapid drop in IgG levels, including the harmful antibodies causing muscle weakness.
Mechanism: FcRn inhibitor that reduces pathogenic IgG antibodies attacking neuromuscular junctions
Side effects and safety
Common side effects include respiratory tract infections, headache, and urinary tract infections. Lowering IgG levels can increase infection risk. Allergic reactions, including anaphylaxis and low blood pressure leading to fainting, have been reported, usually during or within an hour of a dose, and infusion-related reactions can occur with the IV form. The subcutaneous formulation (Hytrulo) may cause injection site reactions.
This is not a complete list of side effects. Talk to your doctor or pharmacist about what to expect and when to seek medical attention.
Taking Efgartigimod alfa
Available as a 1-hour IV infusion (Vyvgart, 10 mg/kg) given weekly for 4 weeks per cycle, or a subcutaneous injection (Vyvgart Hytrulo, approved 2023) given weekly for 4 weeks per cycle. The Hytrulo prefilled syringe can be given at home by patients or caregivers after training. Treatment cycles are repeated based on clinical response.
Availability and cost
Only available as the brand-name product.
First-in-class neonatal Fc receptor (FcRn) blocker that reduces pathogenic IgG antibodies. Available as both IV infusion and subcutaneous injection with novel biologic pricing.
Help paying for Vyvgart
Pick your insurance to see which help fits. Drugmaker copay cards can't be used with Medicare, Medicaid or TRICARE; charity funds are the usual route there.
- Copay help
Eligible commercially insured patients may pay as little as $0 for VYVGART and its administration, up to $25,000 per calendar year.
For: private insurance · source - Infusion cost help
The copay program also covers eligible out-of-pocket costs for drug administration. Massachusetts and Rhode Island residents do not qualify for administration-cost help.
For: private insurance · source - Bridge or quick-start supply
Quick Start Program gives eligible new patients VYVGART Hytrulo at no cost for a limited time if commercial insurance delays access. Must be enrolled in My VYVGART Path.
For: private insurance · source - Insurance and case manager help
A Nurse Case Manager, with access and financial assistance specialists, helps with insurance, benefits review and checking eligibility for financial help.
The official page does not say who qualifies. Ask the program. · source
Good to know: The Quick Start Program covers VYVGART Hytrulo only, not the IV form. mypathenroll.com is argenx's online enrollment portal, not a program information page.
- From a charity · NORD RareCareMyasthenia Gravis Medical Assistance fundOpen
Pays for: Medical and medication costs.
The foundation says: “Accepting new applications and re-enrollments for current year” - From a charity · NORD RareCareMyasthenia Gravis Premium Copay Assistance fundOpen
Pays for: Insurance premiums and copays.
The foundation says: “Accepting new applications and re-enrollments for current year” - From a charity · TotalAssist (formerly PAN Foundation)Myasthenia Gravis fundOpen
Pays for: Out-of-pocket costs for approved medications, up to $10,000 per year. Requires Medicare, Medicaid or TRICARE.
- From a charity · The Assistance FundMyasthenia Gravis fundWaitlist
Pays for: Copays, coinsurance, deductibles and other health-related expenses.
The foundation says: “WAITLIST — Accepting Waitlist Patients. TAF is currently accepting requests to join the enrollment waitlist for this program. Waitlists a…”
Clinical trial results
ADAPT trial showed 68% of AChR-antibody-positive patients responded, with clinically meaningful improvement in daily activities and muscle strength. Rapid onset of action within 1-2 weeks.
Development history
Vyvgart (IV) approved December 2021 for AChR-antibody-positive gMG. Vyvgart Hytrulo (subcutaneous) approved 2023 and later also approved for chronic inflammatory demyelinating polyneuropathy (CIDP). In May 2026 the FDA expanded both Vyvgart and Vyvgart Hytrulo to all adults with gMG, including anti-MuSK positive, anti-LRP4 positive, and triple seronegative disease. Developed by argenx, it pioneered the FcRn inhibitor class in neurology.
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Common questions about Efgartigimod alfa
▸What is Efgartigimod alfa (Vyvgart)?
The first FcRn inhibitor approved for generalized myasthenia gravis. Rapidly lowers the harmful antibodies that attack the connection between nerves and muscles, improving strength within weeks. Since May 2026 it is approved for all adults with generalized myasthenia gravis, including people who test negative for AChR, MuSK and LRP4 antibodies, the only targeted MG drug with that approval.
▸How does Efgartigimod alfa work?
In myasthenia gravis, the immune system makes antibodies (IgG) that attack acetylcholine receptors at the neuromuscular junction, causing muscle weakness. Efgartigimod blocks the neonatal Fc receptor (FcRn), which normally recycles IgG antibodies and keeps their levels high. By blocking this recycling, efgartigimod causes a rapid drop in IgG levels, including the harmful antibodies causing muscle weakness.
▸What are the side effects of Efgartigimod alfa?
Common side effects include respiratory tract infections, headache, and urinary tract infections. Lowering IgG levels can increase infection risk. Allergic reactions, including anaphylaxis and low blood pressure leading to fainting, have been reported, usually during or within an hour of a dose, and infusion-related reactions can occur with the IV form. The subcutaneous formulation (Hytrulo) may cause injection site reactions.
▸How is Efgartigimod alfa taken?
Available as a 1-hour IV infusion (Vyvgart, 10 mg/kg) given weekly for 4 weeks per cycle, or a subcutaneous injection (Vyvgart Hytrulo, approved 2023) given weekly for 4 weeks per cycle. The Hytrulo prefilled syringe can be given at home by patients or caregivers after training. Treatment cycles are repeated based on clinical response.
▸Is Efgartigimod alfa FDA approved?
Yes, Efgartigimod alfa (Vyvgart) is FDA approved (2021) for the treatment of Myasthenia Gravis.
▸What is an FcRn inhibitor and how does it help MG?
FcRn (neonatal Fc receptor) normally recycles IgG antibodies, keeping their levels high. In MG, pathogenic IgG antibodies attack neuromuscular junctions. By blocking FcRn, efgartigimod accelerates the breakdown of all IgG antibodies, including the harmful ones, leading to improved muscle strength.
▸How quickly does efgartigimod start working?
Efgartigimod has a rapid onset of action, with clinically meaningful improvement seen within 1-2 weeks of starting treatment. In the ADAPT trial, 68% of AChR-antibody-positive patients responded to treatment.
▸What is the difference between Vyvgart and Vyvgart Hytrulo?
Vyvgart is the IV infusion formulation (approved December 2021), given weekly for 4 weeks per cycle. Vyvgart Hytrulo is the subcutaneous injection (approved 2023), offering greater convenience for home administration.
▸How are treatment cycles structured?
Efgartigimod is given in cycles rather than continuously. Each cycle involves weekly treatments for 4 weeks, followed by a break. New cycles are started based on clinical response when symptoms return.
▸Does lowering IgG increase infection risk?
Because efgartigimod lowers total IgG levels, there may be an increased risk of infections. Common side effects include respiratory and urinary tract infections. Your doctor will watch for signs of infection during treatment and may delay a treatment cycle if you have an active infection.
▸What patient support is available for Vyvgart?
My VYVGART Path provides disease and product education, insurance benefits verification, financial assistance screening, and access support through dedicated Nurse Case Managers.
▸How does efgartigimod compare to complement inhibitors for MG?
FcRn inhibitors like efgartigimod reduce pathogenic antibodies, while complement inhibitors like eculizumab block downstream immune damage. FcRn inhibitors work across different antibody subtypes, while complement inhibitors specifically target the complement cascade.