Vyvgart Efgartigimod Alfa Injection

1. Indications and Usage
Generalized Myasthenia Gravis: Indicated for the treatment of adult patients with acetylcholine receptor (AChR) antibody-positive generalized myasthenia (gMG).
2. Dosage and Administration
Recommended Dose: The recommended dose is 10 mg/kg administered intravenously once weekly for 4 consecutive weeks.
Weight-Based Dosing: For patients weighing 120 kg or more, the recommended dose is 1200 mg (3 vials) per administration.
Administration: The drug must be diluted with 0.9% sodium chloride injection to a total volume of 125 mL and administered as an intravenous infusion over 1 hour.
Subsequent Cycles: Subsequent treatment cycles should be determined based on clinical assessment.
3. Mechanism of Action
FcRn Antagonist: Efgartigimod alfa is an engineered fragment crystallizable (Fc) fragment of an IgG1 antibody.
IgG Catabolism: It binds to the neonatal Fc receptor (FcRn), blocking the recycling of IgG antibodies. This leads to the accelerated degradation of pathogenic IgG antibodies, including the AChR antibodies responsible for gMG.
4. Safety and Warnings
Infection Risk: Treatment causes transient decreases in serum total IgG levels, which may increase the risk of infections.
Vaccination: Live or live-attenuated vaccines should not be administered during treatment. Vaccination should be evaluated according to immunization guidelines before starting a new treatment cycle.
Hypersensitivity: Hypersensitivity reactions may occur. Patients should be monitored for symptoms of allergic reactions during administration.
5. Adverse Reactions and Clinical Research
Adverse Reactions: The most common adverse reactions include upper respiratory tract infection, headache, diarrhea, nausea, fatigue, and infusion-related reactions.
Clinical Research: Clinical trials have demonstrated that efgartigimod alfa significantly improves muscle strength and daily living activities in patients with gMG.
6. Drug Interactions
Live Vaccines: Concomitant use with live vaccines is contraindicated due to the risk of vaccine-derived infection.
Immunoglobulins: Concomitant use with intravenous immunoglobulin (IVIG) is not recommended as it may interfere with the assessment of treatment efficacy.
7. Pharmaceutical Information
Composition: The active ingredient is efgartigimod alfa. Excipients include sodium dihydrogen phosphate monohydrate, disodium hydrogen phosphate anhydrous, sodium chloride, L-arginine, and polysorbate 80.
Appearance: The solution is sterile, preservative-free, clear to slightly opalescent, and colorless to pale yellow.
Storage: Store in a refrigerator at 2°C to 8°C. Do not freeze or shake.