Vyvgart Efgartigimod Alfa Injection

1. ‌Indications and Usage‌
Indications: Vyvgart (efgartigimod alfa) is indicated for the treatment of adult systemic myasthenia gravis (gMG) patients with positive anti acetylcholine receptor (AChR) antibodies.
This drug works by reducing the levels of pathogenic immunoglobulin G (IgG), improving muscle strength and quality of life.
This indication has been approved by the FDA (first approved in 2023) based on significant reductions in IgG levels and improvements in MG-ADL scores observed in multiple clinical trials.
2. ‌Dosage and Administration‌
Recommended dose: 10 mg/kg intravenous infusion, once a week, for 4 consecutive weeks as a treatment cycle.
Medication can be repeated every 6-9 weeks based on clinical response.
The infusion time should be ≥ 1 hour; If well tolerated, it can be shortened to ≥ 30 minutes in the future.
Dose adjustment: There is no need to adjust the dose based on age, gender, or mild to moderate renal insufficiency. There is limited data on patients with severe renal impairment.
3. ‌Mechanism of Action‌

Vyvgart is a humanized monoclonal antibody fragment (FcRn blocker) that selectively blocks the binding of neonatal Fc receptors (FcRn) to IgG, accelerating the degradation of IgG in the body and reducing total IgG levels, including pathogenic AChR antibodies.

4. ‌Safety and Warnings‌
Infection risk: Due to a decrease in IgG levels, there may be an increased risk of infection. Common infections include respiratory tract infections, urinary tract infections, etc. Before medication, the vaccination status should be evaluated.
Infusion related reactions: About 1% of patients report mild to moderate reactions (such as headache, nausea, fever), usually occurring during or within 1 hour after infusion.
Embryo fetal toxicity: Animal studies have shown that it may cause damage to the fetus. It is recommended that women with fertility potential take effective contraceptive measures during treatment and for at least 6 weeks after the last dose.
Vaccination suggestions: It is recommended to complete all age appropriate vaccinations before starting a new treatment cycle, especially pneumococcal, influenza and COVID-19 vaccines.
5. ‌Adverse Reactions‌
The most common (≥ 10%) adverse reactions are:
Upper respiratory tract infection, headache, respiratory tract infection, nasopharyngitis, flu like symptoms, fatigue, nausea.
Laboratory abnormality:
Temporary decrease in IgG levels (average decrease of 61%), usually returning to baseline 6-9 weeks after the end of the treatment cycle.
The levels of IgM and IgA also showed a slight decrease, but there was no clinically significant impact.
6. ‌Drug Interactions‌
No significant pharmacokinetic interactions were observed with commonly used drugs such as acetylcholinesterase inhibitors, glucocorticoids, and immunosuppressants.
Can be used in combination with other standard MG treatments such as pyridostigmine, prednisone, and azathioprine.
7. ‌Pharmaceutical Information‌
Product Name: Vyvgart ®
Common name: efgartigimod alfa fcab
Dosage form: Freeze dried powder injection for injection (1000 mg/vial)
Administration route: intravenous infusion
R&D company: argenx
FDA First Approval Date: January 2023
Storage conditions: Refrigerate at 2-8 ° C, store away from light, do not freeze