Efgartigimod Alfa

1 INDICATIONS AND USAGE VYVGART is indicated for the treatment of generalized myasthenia gravis (gMG) in adult patients who are anti-acetylcholine receptor (AChR) antibody positive. VYVGART is a neonatal Fc receptor blocker indicated for the treatment of generalized myasthenia gravis (gMG) in adult patients who are anti-acetylcholine receptor (AChR) antibody positive. ( 1 )

2 DOSAGE AND ADMINISTRATION Evaluate the need to administer age-appropriate vaccines according to immunization guidelines before initiation of a new treatment cycle with VYVGART. ( 2.1 ) The recommended dosage is 10 mg/kg administered as an intravenous infusion over one hour once weekly for 4 weeks. In patients weighing 120 kg or more, the recommended dose is 1200 mg per infusion. ( 2.2 ) Administer subsequent treatment cycles based on clinical evaluation. ( 2.2 ) Must be diluted with 0.9% Sodium Chloride Injection, USP prior to administration. ( 2.3 ) Administer as an intravenous infusion over one hour via a 0.2 micron in-line filter. ( 2.3 ) 2.1 Recommended Vaccination Evaluate the need to administer age-appropriate vaccines according to immunization guidelines before initiation of a new treatment cycle with VYVGART. Because VYVGART causes transient reduction in IgG levels, vaccination with live vaccines is not recommended during treatment with VYVGART [see Dosage and Administration (2.2) and Warnings and Precautions (5.1) ] . 2.2 Recommended Dose and Dose Schedules Dilute VYVGART prior to administration. Administer via intravenous infusion only [see Dosage and Administration (2.3) ] . The recommended dosage of VYVGART is 10 mg/kg administered as an intravenous infusion over one hour once weekly for 4 weeks. In patients weighing 120 kg or more, the recommended dose of VYVGART is 1200 mg (3 vials) per infusion. Administer subsequent treatment cycles based on clinical evaluation. If a scheduled infusion is missed, VYVGART may be administered up to 3 days after the scheduled time point. Thereafter, resume the original dosing schedule until the treatment cycle is completed. 2.3 Preparation and Administration Instructions Prior to administration, VYVGART single-dose vials require dilution in 0.9% Sodium Chloride Injection, USP, to make a total volume to be administered of 125 mL (see Preparation ) . Check that the VYVGART solution is clear to slightly opalescent and colorless to slightly yellow. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. Do not use if opaque particles, discoloration, or other foreign particles are present. Use aseptic technique when preparing the VYVGART diluted solution for intravenous infusion. Each vial is for single-dose only. Discard any unused portion. Preparation Calculate the dose (mg), total drug volume (mL) of VYVGART solution required, and the number of vials needed based on the recommended dose according to the patient's body weight [see Dosage and Administration (2.2) ] . Each vial contains a total of 400 mg of VYVGART at a concentration of 20 mg per mL. Gently withdraw the calculated dose of VYVGART from the vial(s) with a sterile syringe and needle. Discard any unused portion of the vials. Dilute the withdrawn VYVGART with 0.9% Sodium Chloride Injection, USP to make a total volume of 125 mL for intravenous infusion. Gently invert the infusion bag containing the diluted VYVGART without shaking to ensure thorough mixing of the product and the diluent. The diluted solution can be administered using polyethylene (PE), polyvinyl chloride (PVC), ethylene vinyl acetate (EVA), or ethylene/polypropylene copolymer bags (polyolefins bags), and with PE, PVC, EVA, or polyurethane/polypropylene infusion lines. Storage Conditions of the Diluted Solution VYVGART does not contain preservatives. Administer immediately after dilution and complete the infusion within 4 hours of dilution. If immediate use is not possible, the diluted solution may be stored refrigerated at 2°C to 8°C (36°F to 46°F) for up to 8 hours. Do not freeze. Protect from light. Allow the diluted drug to reach room temperature before administration. Complete the infusion within 4 hours of removal from the refrigerator. Do not heat the diluted drug in any manner other than via ambient air. Administration VYVGART should be administered via intravenous infusion by a healthcare professional. Visually inspect VYVGART diluted solution for particles or discoloration prior to administration. Do not use if it is discolored, or if opaque or foreign particles are seen. Infuse the total 125 mL of diluted solution intravenously over one hour via a 0.2 micron in-line filter. After administration of VYVGART, flush the entire line with 0.9% Sodium Chloride Injection, USP. Monitor patients during administration and for 1 hour thereafter for clinical signs and symptoms of hypersensitivity reactions. If a hypersensitivity reaction occurs during administration, discontinue administration of VYVGART and institute appropriate supportive measures [see Warnings and Precautions (5.2) ]. Other medications should not be injected into infusion side ports or mixed with VYVGART.

6 ADVERSE REACTIONS The following clinically significant adverse reactions are described elsewhere in the labeling: Infections [see Warnings and Precautions (5.1) ] Hypersensitivity Reactions [see Warnings and Precautions (5.2) ] Infusion-Related Reactions [see Warnings and Precautions (5.3) ] Most common adverse reactions ( ≥ 10%) in patients treated with gMG are respiratory tract infections, headache, and urinary tract infection. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact argenx at 1-833-argx411 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. In clinical studies, the safety of VYVGART has been evaluated in 246 patients who received at least one dose of VYVGART, including 57 patients exposed to at least 7 treatment cycles and 8 patients exposed to at least 10 treatment cycles. In a placebo-controlled study (Study 1) in patients with gMG, 84 patients received VYVGART 10 mg/kg [see Clinical Studies (14) ]. Of these 84 patients, approximately 75% were female, 82% were White, 11% were Asian, and 8% were of Hispanic or Latino ethnicity. The mean age at study entry was 46 years (range 19 to 78). The minimum time to initiate a subsequent cycle, specified by study protocol, was 28 days from the last administration of the previous treatment cycle. On average, VYVGART-treated patients received 2 cycles in Study 1. The mean and median times to the second treatment cycle were 54 days and 50 days from the last administration of the first treatment cycle, respectively, for VYVGART-treated patients. Adverse reactions reported in at least 5% of patients treated with VYVGART and more frequently than placebo are summarized in Table 1. The most common adverse reactions (reported in at least 10% of VYVGART-treated patients) were respiratory tract infection, headache, and urinary tract infection. Table 1: Adverse Reactions in ≥ 5% of Patients Treated with VYVGART and More Frequently than in Placebo-Treated Patients in Study 1 (Safety Population) Adverse reaction VYVGART (N=84) % Placebo (N=83) % Respiratory tract infection 33 29 Headache Headache includes migraine and procedural headache. 32 29 Urinary tract infection 10 5 Paraesthesia Paraesthesia includes oral hypoesthesia, hypoesthesia, and hyperesthesia. 7 5 Myalgia 6 1 The safety of initiating subsequent cycles between 7 and 28 days from the last administration of the previous treatment cycle was assessed in 60 patients. Of these patients, 63% were exposed to treatment for over a year when cycles were initiated less than 4 weeks after the last administration. Safety in these patients was similar to that seen in Study 1. 6.2 Postmarketing Experience The following adverse reactions have been identified during postapproval use of VYVGART. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Immune System Disorders: Hypersensitivity reactions including anaphylaxis and hypotension, and infusion-related reactions [see Warnings and Precautions (5.2 , 5.3) ]. 6.3 Immunogenicity As with all therapeutic proteins, there is potential for immunogenicity. The detection of antibody formation is highly dependent on the sensitivity and specificity of the assay. Additionally, the observed incidence of antibody (including neutralizing antibody) positivity in an assay may be influenced by several factors including assay methodology, sample handling, timing of sample collection, concomitant medications, and underlying disease. For these reasons, comparison of the incidence of antibodies to VYVGART in the studies described below with the incidence of antibodies in other studies or to other products may be misleading. In up to 26 weeks of treatment in Study 1, 20% (17/83) of patients developed antibodies to VYVGART. Seven percent (6/83) of patients developed neutralizing antibodies. Because few patients tested positive for anti-efgartigimod alfa-fcab antibodies and neutralizing antibodies, the available data are too limited to make definitive conclusions regarding immunogenicity and the effect on pharmacokinetics, safety, or efficacy of VYVGART.

12.3 Pharmacokinetics Efgartigimod alfa-fcab exhibits linear pharmacokinetics, and following single doses of efgartigimod alfa-fcab, exposures increase proportionally up to 50 mg/kg (5 times the recommended dosage). Distribution The volume of distribution is 15 to 20L. Metabolism and Elimination Efgartigimod alfa-fcab is expected to be degraded by proteolytic enzymes into small peptides and amino acids. The terminal half-life is 80 to 120 hours (3 to 5 days). After a single intravenous dose of 10 mg/kg efgartigimod alfa-fcab in healthy subjects, less than 0.1% of the administered dose was recovered in urine. Specific Populations Age, Sex, and Race A population pharmacokinetics analysis assessing the effects of age, sex, and race did not suggest any clinically significant impact of these covariates on efgartigimod alfa-fcab exposures. Patients with Renal Impairment No dedicated pharmacokinetic study has been performed in patients with renal impairment. A population PK analysis of data from the VYVGART clinical studies indicated that patients with mild renal impairment (eGFR 60-89 mL/min/1.72m²) had 22% increase in exposure relative to the exposure in patients with normal renal function [see Use in Specific Populations (8.6) ]. Patients with Hepatic Impairment No dedicated pharmacokinetic study has been performed in patients with hepatic impairment. Hepatic impairment is not expected to affect the pharmacokinetics of efgartigimod alfa-fcab. Drug Interaction Studies Clinical drug interactions studies have not been performed with efgartigimod alfa-fcab. P450 Enzymes Efgartigimod alfa-fcab is not metabolized by cytochrome P450 enzymes; therefore, interactions with concomitant medications that are substrates, inducers, or inhibitors of cytochrome P450 enzymes are unlikely. Drug Interactions with Other Drugs or Biological Products Efgartigimod alfa-fcab may decrease concentrations of compounds that bind to the human FcRn [see Drug Interactions (7.1) ].