Efgartigimod Alfa

Efgartigimod Alfa is a prescription medication used for the treatment of generalized myasthenia gravis (gMG)  in adults who are anti-acetylcholine receptor (AChR) antibody positive.

• Efgartigimod Alfa is available under the following different brand names: Vyvgart, efgartigimod Alfa-fcab

Common side effects of Efgartigimod Alfa include:

• respiratory tract infections
• headache
• urinary tract infection
• numbness and tingling
• muscle pain

Serious side effects of Efgartigimod Alfa include:

• hives
• difficulty breathing
• swelling of the face, lips, tongue, or throat
• severe dizziness
• fever
• sore throat

Rare side effects of Efgartigimod Alfa include:

• none

Seek medical care or call 911 at once if you have the following serious side effects:

• Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, coordination loss, unsteady, very stiff muscles, high fever, profuse sweating, or tremors.
• Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights.
• Serious heart symptoms include fast, irregular, or pounding heartbeats; fluttering in the chest; shortness of breath; sudden dizziness, lightheadedness, or passing out.

This is not a complete list of side effects and other serious side effects or health problems that may occur because of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

Adult dosage

Injectable solution

• 400 mg/20 mL

Myasthenia gravis

Adult dosage

• Weight below 120 kg: 10 mg/kg IV every week for 4 weeks. 
• Weight more than 120 kg: 1200 mg IV every week for 4 weeks
• Administer subsequent treatment cycles based on clinical evaluation
• The safety of initiating subsequent cycles sooner than 50 days from the start of the previous treatment cycle has not been established

Dosage Considerations – Should be Given as Follows:

• See “Dosages”

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, healthcare provider, or pharmacist first.

• Efgartigimod Alfa has severe interactions with the following drug:
  • upadacitinib
• Efgartigimod Alfa has serious interactions with no other drugs
• Efgartigimod Alfa has moderate interactions with at least 71 other drugs
• Efgartigimod Alfa has no noted minor interactions with any other drugs

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist about all the products you use. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your healthcare professional or doctor for additional medical advice, health questions, or concerns.

Contraindications

• None

Effects of drug abuse

• None

Short-Term Effects

• See “What Are Side Effects Associated with Using Efgartigimod Alfa?”

Long-Term Effects

• See “What Are Side Effects Associated with Using Efgartigimod Alfa?”

Cautions

• Hypersensitivity reactions (such as rash, angioedema, and dyspnea) observed; monitor patients during administration and for 1 hour after infusion for clinical signs and symptoms of hypersensitivity reactions; if a reaction occurs during administration, discontinue infusion and institute appropriate supportive measures if needed
• Immunization
  • Immunization with vaccines during treatment has not been studied; the safety of immunization with live or live, attenuated vaccines and the response to immunization with any vaccine is unknown
  • Vaccination with live, attenuated, or live vaccines is not recommended during treatment
  • Evaluate the need to administer age-appropriate vaccines according to immunization guidelines before initiation of a new treatment cycle
• Infections
  • May increase the risk for infection
  • Most infections and hematologic abnormalities were mild to moderate in severity
  • Delay administration in patients with an active infection until the infection is resolved
  • During treatment, monitor for clinical signs and symptoms of infections
  • If a serious infection occurs, administer appropriate treatment, and consider withholding therapy until the infection is resolved
• Drug interactions overview
  • Fc receptor antagonists
    • Closely monitor for reduced effectiveness of medications that bind to the human neonatal Fc receptor (FcRn)
    • Efgartigimod may decrease concentrations of drugs that bind to human FcRn (eg, immunoglobulin products, monoclonal antibodies, or antibody derivatives containing the human Fc domain of the immunoglobulin G [IgG] subclass)
    • When concomitant, long-term use of such medications is essential for patient care, consider discontinuing therapy and using alternative therapies

Pregnancy and Lactation

• No data available on the drug’s use during pregnancy
• There is no evidence of adverse developmental outcomes following the administration of up to 100 mg/kg/day of Efgartigimod Alfa in rats and rabbits
• Fetal or neonatal adverse reactions
• Monoclonal antibodies are increasingly transported across the placenta as pregnancy progresses, with the largest amount transferred during the third trimester
• Efgartigimod Alfa-fcab may be transmitted from the mother to the developing fetus
• May reduce maternal IgG antibody levels, and reduction in passive protection for the newborn is anticipated
• Consider risks and benefits before administering live or live, attenuated vaccines to infants exposed in utero
• Lactation
  • There is no information regarding the presence of efgartigimod Alfa-fcab in human milk and its effects on breastfed infants or on milk production
  • Maternal IgG is known to be present in human milk