Version July 2025
Dosage guidance:
Safety: Do NOT substitute efgartigimod alfa (for IV administration) and efgartigimod alfa/hyaluronidase (for SUBQ use); products have different dosing and are NOT interchangeable. Evaluate need to administer age-appropriate vaccines according to immunization guidelines prior to initiation of new treatment cycle; immunization with live vaccines is not recommended during treatment due to transient reduction in IgG levels during therapy. Delay administration in patients with active infection until the infection is resolved.
Clinical considerations: For use as chronic immunosuppressive therapy in patients with anti–acetylcholine receptor antibody positive (AChR+) myasthenia gravis as monotherapy (eg, in patients who cannot tolerate glucocorticoids), as bridge therapy with slower-acting immunosuppressive agents, or in combination with glucocorticoids in patients with glucocorticoid-resistant or glucocorticoid-dependent disease (Ref).
Myasthenia gravis, generalized (alternative agent):
IV: 10 mg/kg (maximum dose: 1,200 mg) once weekly for 4 weeks. Subsequent treatment cycles of 10 mg/kg (maximum dose: 1,200 mg) once weekly for 4 weeks may be administered based on clinical evaluation and no sooner than 50 days from the start of the previous treatment cycle.
Missed doses: If a dose is missed, administer as soon as possible within 3 days after the missed dose; dosing can then be resumed on the usual day of administration to complete 4 infusions for a full cycle. If a dose is missed by ≥3 days after the originally scheduled dose, administer subsequent doses with 1 week between infusions to complete 4 infusions for a full cycle. If significant time has elapsed between doses, providers should consider individual patient circumstances when deciding whether to continue the current cycle or begin a new cycle (Ref).
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
eGFR ≥60 mL/minute/1.73 m2: No dosage adjustment needed.
eGFR <60 mL/minute/1.73 m2: There are no dosage adjustments provided in the manufacturer's labeling (has not been studied).
There are no dosage adjustments provided in the manufacturer’s labeling (has not been studied); hepatic impairment is not expected to impact the clearance of efgartigimod alfa.
Hypersensitivity reaction: Discontinue infusion and initiate supportive management.
Infection, severe: Initiate appropriate treatment; consider withholding efgartigimod alfa until resolution of infection.
Infusion reaction, mild to moderate: May rechallenge with close monitoring, slower infusion rate, and premedications.
Infusion reaction, severe: Discontinue infusion and initiate supportive management.
Refer to adult dosing.
The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified. Adverse reactions reported in adults.
>10%:
Hematologic & oncologic: Decreased neutrophils (13%), decreased white blood cell count (12%), lymphocytopenia (28%)
Immunologic: Antibody development (20%; neutralizing: 7%)
Nervous system: Headache (32%, including migraine)
Respiratory: Respiratory tract infection (33%)
1% to 10%:
Genitourinary: Urinary tract infection (10%)
Nervous system: Paresthesia (7%, including hyperesthesia, hypoesthesia)
Neuromuscular & skeletal: Myalgia (6%)
Frequency not defined:
Hypersensitivity: Hypersensitivity reaction (including angioedema)
Infection: Infection
Postmarketing: Hypersensitivity: Anaphylaxis, infusion-related reaction
Serious hypersensitivity (eg, anaphylaxis, hypotension leading to syncope) to efgartigimod alfa or any component of the formulation.
Concerns related to adverse effects:
• Infections: Infections, including urinary tract infections and respiratory tract infections, have been reported. In addition to infections, the risk of below normal white blood cells, lymphocyte counts, and neutrophil counts have been observed with efgartigimod treatment. The majority of infections and hematological changes were mild to moderate in severity. Delay treatment in patients with an active infection.
• Hypersensitivity reaction: Hypersensitivity reactions, including angioedema, dyspnea, and rash, may occur; mild to moderate reactions usually occurred within 1 hour to 3 weeks of administration. Anaphylaxis and hypotension leading to syncope have also been reported during or within 1 hour of administration; discontinuation of infusion and permanent treatment discontinuation were needed in some patients.
• Infusion reaction: Infusion-related reactions, including abdominal pain, back pain, chills, hypertension, shivering, and thoracic pain, may occur; usually occurred during or within 1 hour of administration and have led to discontinuation of therapy. Consider risks and benefits of readministration in patients with a severe infusion-related reaction.
Dosage form specific issues:
• Polysorbate 80: Some dosage forms may contain polysorbate 80 (also known as Tweens). Hypersensitivity reactions, usually a delayed reaction, have been reported following exposure to pharmaceutical products containing polysorbate 80 in certain individuals (Isaksson 2002; Lucente 2000; Shelley 1995). Thrombocytopenia, ascites, pulmonary deterioration, and renal and hepatic failure have been reported in premature neonates after receiving parenteral products containing polysorbate 80 (Alade 1986; CDC 1984). See manufacturer's labeling.
Other warnings/precautions:
• Immunizations: Evaluate need to administer age-appropriate vaccines according to immunization guidelines prior to initiation of new treatment cycle. Avoid the use of live vaccines in patients undergoing efgartigimod treatment.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Solution, Intravenous [preservative free]:
Vyvgart: Efgartigimod alfa-fcab 400 mg/20 mL (20 mL) [contains polysorbate 80]
No
Solution (Vyvgart Intravenous)
400 mg/20 mL (per mL): $371.42
Disclaimer: A representative AWP (Average Wholesale Price) price or price range is provided as reference price only. A range is provided when more than one manufacturer's AWP price is available and uses the low and high price reported by the manufacturers to determine the range. The pricing data should be used for benchmarking purposes only, and as such should not be used alone to set or adjudicate any prices for reimbursement or purchasing functions or considered to be an exact price for a single product and/or manufacturer. Medi-Span expressly disclaims all warranties of any kind or nature, whether express or implied, and assumes no liability with respect to accuracy of price or price range data published in its solutions. In no event shall Medi-Span be liable for special, indirect, incidental, or consequential damages arising from use of price or price range data. Pricing data is updated monthly.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Solution, Intravenous:
Vyvgart: Efgartigimod alfa-fcab 400 mg/20 mL (20 mL) [contains polysorbate 80]
Note: Check label to ensure appropriate product is administered; efgartigimod alfa/hyaluronidase (SUBQ) and efgartigimod alfa (IV) are different products and are NOT interchangeable.
IV: Allow refrigerated infusion bag to reach room temperature prior to administration. Infuse over 1 hour via a 0.2 micron in-line filter; do not administer as IV push or bolus. Following administration, flush entire line with NS. Monitor patient during administration and for at least 1 hour following completion of infusion for signs/symptoms of hypersensitivity reaction.
Myasthenia gravis, generalized: Treatment of generalized myasthenia gravis in adults who are anti–acetylcholine receptor antibody positive (AChR+).
Sound-alike/look-alike issues:
Vyvgart may be confused with Vyvgart Hytrulo.
Efgartigimod alfa may be confused with efgartigimod alfa/hyaluronidase.
None known.
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the drug interactions program by clicking on the “Launch drug interactions program” link above.
Abrocitinib: May increase immunosuppressive effects of Immunosuppressants (Therapeutic Immunosuppressant Agents). Risk X: Avoid
Antithymocyte Globulin (Equine): Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase adverse/toxic effects of Antithymocyte Globulin (Equine). Specifically, these effects may be unmasked if the dose of immunosuppressive therapy is reduced. Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase immunosuppressive effects of Antithymocyte Globulin (Equine). Specifically, infections may occur with greater severity and/or atypical presentations. Risk C: Monitor
Baricitinib: Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase immunosuppressive effects of Baricitinib. Risk X: Avoid
BCG Products: Immunosuppressants (Therapeutic Immunosuppressant Agents) may decrease therapeutic effects of BCG Products. Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase adverse/toxic effects of BCG Products. Specifically, the risk of vaccine-associated infection may be increased. Risk X: Avoid
Brincidofovir: Immunosuppressants (Therapeutic Immunosuppressant Agents) may decrease therapeutic effects of Brincidofovir. Risk C: Monitor
Brivudine: May increase adverse/toxic effects of Immunosuppressants (Therapeutic Immunosuppressant Agents). Risk X: Avoid
Chikungunya Vaccine (Live): Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase adverse/toxic effects of Chikungunya Vaccine (Live). Specifically, the risk of vaccine-associated infection may be increased. Immunosuppressants (Therapeutic Immunosuppressant Agents) may decrease therapeutic effects of Chikungunya Vaccine (Live). Risk X: Avoid
Cladribine: Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase immunosuppressive effects of Cladribine. Risk X: Avoid
Coccidioides immitis Skin Test: Coadministration of Immunosuppressants (Therapeutic Immunosuppressant Agents) and Coccidioides immitis Skin Test may alter diagnostic results. Management: Consider discontinuing therapeutic immunosuppressants several weeks prior to coccidioides immitis skin antigen testing to increase the likelihood of accurate diagnostic results. Risk D: Consider Therapy Modification
COVID-19 Vaccine (Inactivated Virus): Immunosuppressants (Therapeutic Immunosuppressant Agents) may decrease therapeutic effects of COVID-19 Vaccine (Inactivated Virus). Risk C: Monitor
COVID-19 Vaccine (mRNA): Immunosuppressants (Therapeutic Immunosuppressant Agents) may decrease therapeutic effects of COVID-19 Vaccine (mRNA). Management: Give a 3-dose primary series for all patients aged 6 months and older taking immunosuppressive medications or therapies. Booster doses are recommended for certain age groups. See CDC guidance for details. Risk D: Consider Therapy Modification
COVID-19 Vaccine (Subunit): Immunosuppressants (Therapeutic Immunosuppressant Agents) may decrease therapeutic effects of COVID-19 Vaccine (Subunit). Risk C: Monitor
Dengue Tetravalent Vaccine (Live): Immunosuppressants (Therapeutic Immunosuppressant Agents) may decrease therapeutic effects of Dengue Tetravalent Vaccine (Live). Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase adverse/toxic effects of Dengue Tetravalent Vaccine (Live). Specifically, the risk of vaccine-associated infection may be increased. Risk X: Avoid
Denosumab: Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase immunosuppressive effects of Denosumab. Management: Consider the risk of serious infections versus the potential benefits of coadministration of denosumab and immunosuppressants. If combined, monitor for signs/symptoms of serious infections. Risk D: Consider Therapy Modification
Deucravacitinib: May increase immunosuppressive effects of Immunosuppressants (Therapeutic Immunosuppressant Agents). Risk X: Avoid
Etrasimod: May increase immunosuppressive effects of Immunosuppressants (Therapeutic Immunosuppressant Agents). Risk X: Avoid
Fc Receptor-Binding Agents: Efgartigimod Alfa may decrease therapeutic effects of Fc Receptor-Binding Agents. Risk C: Monitor
Filgotinib: May increase immunosuppressive effects of Immunosuppressants (Therapeutic Immunosuppressant Agents). Risk X: Avoid
Inebilizumab: Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase immunosuppressive effects of Inebilizumab. Risk C: Monitor
Influenza Virus Vaccines: Immunosuppressants (Therapeutic Immunosuppressant Agents) may decrease therapeutic effects of Influenza Virus Vaccines. Management: Administer influenza vaccines at least 2 weeks prior to initiating immunosuppressants if possible. If vaccination occurs less than 2 weeks prior to or during therapy, revaccinate 2 to 3 months after therapy discontinued if immune competence restored. Risk D: Consider Therapy Modification
Leflunomide: Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase immunosuppressive effects of Leflunomide. Management: Increase the frequency of chronic monitoring of platelet, white blood cell count, and hemoglobin or hematocrit to monthly, instead of every 6 to 8 weeks, if leflunomide is coadministered with immunosuppressive agents. Risk D: Consider Therapy Modification
Mumps- Rubella- or Varicella-Containing Live Vaccines: Immunosuppressants (Therapeutic Immunosuppressant Agents) may decrease therapeutic effects of Mumps- Rubella- or Varicella-Containing Live Vaccines. Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase adverse/toxic effects of Mumps- Rubella- or Varicella-Containing Live Vaccines. Specifically, the risk of vaccine-associated infection may be increased. Risk X: Avoid
Nadofaragene Firadenovec: Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase adverse/toxic effects of Nadofaragene Firadenovec. Specifically, the risk of disseminated adenovirus infection may be increased. Risk X: Avoid
Natalizumab: Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase immunosuppressive effects of Natalizumab. Risk X: Avoid
Ocrelizumab: Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase immunosuppressive effects of Ocrelizumab. Risk C: Monitor
Ofatumumab: Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase immunosuppressive effects of Ofatumumab. Risk C: Monitor
Pidotimod: Immunosuppressants (Therapeutic Immunosuppressant Agents) may decrease therapeutic effects of Pidotimod. Risk C: Monitor
Pimecrolimus: Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase immunosuppressive effects of Pimecrolimus. Risk X: Avoid
Pneumococcal Vaccines: Immunosuppressants (Therapeutic Immunosuppressant Agents) may decrease therapeutic effects of Pneumococcal Vaccines. Risk C: Monitor
Poliovirus Vaccine (Live/Trivalent/Oral): Immunosuppressants (Therapeutic Immunosuppressant Agents) may decrease therapeutic effects of Poliovirus Vaccine (Live/Trivalent/Oral). Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase adverse/toxic effects of Poliovirus Vaccine (Live/Trivalent/Oral). Specifically, the risk of vaccine-associated infection may be increased. Risk X: Avoid
Polymethylmethacrylate: Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase hypersensitivity effects of Polymethylmethacrylate. Management: Use caution when considering use of bovine collagen-containing implants such as the polymethylmethacrylate-based Bellafill brand implant in patients who are receiving immunosuppressants. Consider use of additional skin tests prior to administration. Risk D: Consider Therapy Modification
Rabies Vaccine: Immunosuppressants (Therapeutic Immunosuppressant Agents) may decrease therapeutic effects of Rabies Vaccine. Management: Complete rabies vaccination at least 2 weeks before initiation of immunosuppressant therapy if possible. If combined, check for rabies antibody titers, and if vaccination is for post exposure prophylaxis, administer a 5th dose of the vaccine. Risk D: Consider Therapy Modification
Ritlecitinib: Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase immunosuppressive effects of Ritlecitinib. Risk X: Avoid
Ruxolitinib (Topical): Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase immunosuppressive effects of Ruxolitinib (Topical). Risk X: Avoid
Sipuleucel-T: Immunosuppressants (Therapeutic Immunosuppressant Agents) may decrease therapeutic effects of Sipuleucel-T. Management: Consider reducing the dose or discontinuing the use of immunosuppressants prior to initiating sipuleucel-T therapy. Risk D: Consider Therapy Modification
Sphingosine 1-Phosphate (S1P) Receptor Modulators: May increase immunosuppressive effects of Immunosuppressants (Therapeutic Immunosuppressant Agents). Risk C: Monitor
Tacrolimus (Topical): Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase immunosuppressive effects of Tacrolimus (Topical). Risk X: Avoid
Talimogene Laherparepvec: Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase adverse/toxic effects of Talimogene Laherparepvec. Specifically, the risk of infection from the live, attenuated herpes simplex virus contained in talimogene laherparepvec may be increased. Risk X: Avoid
Tertomotide: Immunosuppressants (Therapeutic Immunosuppressant Agents) may decrease therapeutic effects of Tertomotide. Risk X: Avoid
Tofacitinib: Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase immunosuppressive effects of Tofacitinib. Management: Coadministration of tofacitinib with potent immunosuppressants is not recommended. Use with non-biologic disease-modifying antirheumatic drugs (DMARDs) was permitted in psoriatic arthritis clinical trials. Risk X: Avoid
Typhoid Vaccine: Immunosuppressants (Therapeutic Immunosuppressant Agents) may decrease therapeutic effects of Typhoid Vaccine. Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase adverse/toxic effects of Typhoid Vaccine. Specifically, the risk of vaccine-associated infection may be increased. Risk X: Avoid
Ublituximab: Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase immunosuppressive effects of Ublituximab. Risk C: Monitor
Upadacitinib: Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase immunosuppressive effects of Upadacitinib. Risk X: Avoid
Vaccines (Live): Immunosuppressants (Therapeutic Immunosuppressant Agents) may decrease therapeutic effects of Vaccines (Live). Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase adverse/toxic effects of Vaccines (Live). Specifically, the risk of vaccine-associated infection may be increased. Risk X: Avoid
Vaccines (Non-Live/Inactivated/Non-Replicating): Immunosuppressants (Therapeutic Immunosuppressant Agents) may decrease therapeutic effects of Vaccines (Non-Live/Inactivated/Non-Replicating). Management: Give non-live/inactivated/non-replicating vaccines at least 2 weeks prior to starting immunosuppressants when possible. Patients vaccinated less than 14 days before or during therapy should be revaccinated at least 2 to 3 months after therapy is complete. Risk D: Consider Therapy Modification
Yellow Fever Vaccine: Immunosuppressants (Therapeutic Immunosuppressant Agents) may decrease therapeutic effects of Yellow Fever Vaccine. Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase adverse/toxic effects of Yellow Fever Vaccine. Specifically, the risk of vaccine-associated infection may be increased. Risk X: Avoid
Zoster Vaccine (Live/Attenuated): Immunosuppressants (Therapeutic Immunosuppressant Agents) may increase adverse/toxic effects of Zoster Vaccine (Live/Attenuated). Specifically, the risk of vaccine-associated infection may be increased. Immunosuppressants (Therapeutic Immunosuppressant Agents) may decrease therapeutic effects of Zoster Vaccine (Live/Attenuated). Risk X: Avoid
Patients planning to become pregnant were not included in an original study (Howard 2021).
Sexually active male patients were instructed to use effective contraception during treatment and for 90 days after the last dose during an initial study (Howard 2021).
Adverse events were not observed in animal reproduction studies.
Efgartigimod alfa is a human IgG1 antibody fragment; human IgG is known to cross the placenta as pregnancy progresses. The lowest exposure would be expected during the period of organogenesis and the highest during the third trimester. Pregnant patients were not included in an original study (Howard 2021).
When treatment for myasthenia gravis in pregnancy is required, agents other than efgartigimod alfa are currently recommended (Sanders 2016).
Data collection to monitor pregnancy and infant outcomes following exposure to efgartigimod alfa is ongoing. Health care providers are encouraged to enroll patients exposed to efgartigimod alfa during pregnancy in pregnancy registry (1-855-272-6524 or https://www.vyvgartpregnancy.com). Patients may also enroll themselves.
It is not known if efgartigimod alfa is present in breast milk. However, efgartigimod alfa is a human IgG1 antibody fragment; human IgG is known to be present in breast milk.
Lactating patients were not included in an original study (Howard 2021). According to the manufacturer, the decision to breastfeed during therapy should consider the risk of infant exposure, the benefits of breastfeeding to the infant, and the benefits of treatment to the mother.
Signs and symptoms of hypersensitivity reaction (during infusion and for 1 hour after infusion completion), infusion reaction, and infection.
Efgartigimod alfa-fcab is a human IgG1 antibody fragment that binds to the neonatal Fc receptor (FcRn), resulting in the reduction of circulating IgG.
Distribution: Vd: 15 to 20 L.
Metabolism: Degraded by proteolytic enzymes into small peptides and amino acids.
Half-life elimination: Terminal: 80 to 120 hours (3 to 5 days).
Excretion: Proteolysis; urine (<0.1%).
