Efgartigimod alfa

12.1 Mechanism of Action VYVGART HYTRULO is a coformulation of efgartigimod alfa and hyaluronidase. Efgartigimod alfa is a human IgG1 antibody fragment that binds to the neonatal Fc receptor (FcRn), resulting in the reduction of circulating IgG. Hyaluronidase increases permeability of the subcutaneous tissue by depolymerizing hyaluronan. This effect is transient, and permeability of the subcutaneous tissue is restored within 24 to 48 hours.

1 INDICATIONS AND USAGE VYVGART HYTRULO is indicated for the treatment of adult patients with: generalized myasthenia gravis (gMG) who are anti-acetylcholine receptor (AChR) antibody positive chronic inflammatory demyelinating polyneuropathy (CIDP) VYVGART HYTRULO is a combination of efgartigimod alfa, a neonatal Fc receptor blocker, and hyaluronidase, an endoglycosidase, indicated for the treatment of adult patients with: generalized myasthenia gravis (gMG) who are anti-acetylcholine receptor (AChR) antibody positive ( 1 ) chronic inflammatory demyelinating polyneuropathy (CIDP) ( 1 )

2 DOSAGE AND ADMINISTRATION See Full Prescribing Information for instructions on dosage, preparation, and administration. ( 2.1 , 2.2 , 2.3 , 2.4 , 2.5 ) Evaluate the need to administer age-appropriate vaccines according to immunization guidelines before initiation of a new treatment cycle with VYVGART HYTRULO. ( 2.1 ) Important Administration Information VYVGART HYTRULO is for subcutaneous use only. ( 2.2 ) Prefilled syringe can be administered by patients and/or caregivers. ( 2.2 ) Vial to be administered with a winged infusion set by a healthcare professional only. ( 2.2 ) gMG: recommended dose and dose schedule Administer in cycles of once weekly injections for 4 weeks. ( 2.3 ) Prefilled syringe: 1,000 mg efgartigimod alfa and 10,000 units hyaluronidase administered over 20 to 30 seconds. ( 2.3 ) Vial: 1,008 mg efgartigimod alfa and 11,200 units hyaluronidase over 30 to 90 seconds. ( 2.3 ) Administer subsequent treatment cycles based on clinical evaluation. ( 2.3 ) CIDP: recommended dose and dose schedule Administer as once weekly injections. ( 2.4 ) Prefilled syringe: 1,000 mg efgartigimod alfa and 10,000 units hyaluronidase administered over approximately 20 to 30 seconds. ( 2.4 ) Vial: 1,008 mg efgartigimod alfa and 11,200 units hyaluronidase over 30 to 90 seconds. ( 2.4 ) 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 HYTRULO. Because VYVGART HYTRULO causes transient reduction in IgG levels, vaccination with live vaccines is not recommended during treatment with VYVGART HYTRULO [see Dosage and Administration (2.3) and Warnings and Precautions (5.1) ] . 2.2 Important Dosage and Administration Instructions VYVGART HYTRULO is for subcutaneous use only. Do not administer intravenously. Do not dilute VYVGART HYTRULO. Single-Dose Prefilled Syringe VYVGART HYTRULO prefilled syringe may be administered by patients and/or caregivers after proper instruction in subcutaneous injection technique [see Instructions for Use ] . Single-Dose Vial VYVGART HYTRULO vial is to be administered with a winged infusion set by a healthcare professional only [see Dosage and Administration (2.4) ]. 2.3 Recommended Dosage for gMG Single-Dose Prefilled Syringe The recommended dosage of VYVGART HYTRULO prefilled syringe is 1,000 mg / 10,000 units (1,000 mg efgartigimod alfa and 10,000 units hyaluronidase) administered subcutaneously over approximately 20 to 30 seconds in cycles of once weekly injections for 4 weeks. Single-Dose Vial The recommended dosage of VYVGART HYTRULO vial is 1,008 mg / 11,200 units (1,008 mg efgartigimod alfa and 11,200 units hyaluronidase) administered subcutaneously over approximately 30 to 90 seconds in cycles of once weekly injections for 4 weeks. General Dosage Considerations Administer subsequent treatment cycles according to clinical evaluation. If a scheduled dose is missed, VYVGART HYTRULO may be administered up to 3 days after the scheduled time point. Thereafter, resume the original dosing schedule until the treatment cycle is completed. 2.4 Recommended Dosage for CIDP Single-Dose Prefilled Syringe The recommended dosage of VYVGART HYTRULO prefilled syringe is 1,000 mg / 10,000 units (1,000 mg efgartigimod alfa and 10,000 units hyaluronidase) administered subcutaneously over approximately 20 to 30 seconds as once weekly injections. Single-Dose Vial The recommended dosage of VYVGART HYTRULO vial is 1,008 mg / 11,200 units (1,008 mg efgartigimod alfa and 11,200 units hyaluronidase) administered subcutaneously over approximately 30 to 90 seconds as once weekly injections. General Dosage Considerations If a scheduled injection is missed, VYVGART HYTRULO may be administered up to 3 days after the scheduled time point. Thereafter, resume the original dosing schedule. Not all patients respond to VYVGART HYTRULO . Consider the appropriateness of continuing treatment in patients who experience worsening of neurological symptoms after starting VYVGART HYTRULO [see Adverse Reactions (6.2) and Clinical Studies (14.2) ]. 2.5 Preparation and Administration Instructions Single-Dose Prefilled Syringe Take the VYVGART HYTRULO prefilled syringe out of the refrigerator at least 30 minutes before injecting to allow it to reach room temperature [see How Supplied/Storage and Handling (16) ] . Do not use external heat sources to bring the syringe to room temperature. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. Visually inspect that the prefilled syringe solution is yellowish, clear to opalescent and devoid of particulate matter. Do not use if visible particles are present. Each prefilled syringe is for one-time use only. To administer VYVGART HYTRULO prefilled syringe, use a safety needle that is 25G, 5/8 inches in length, and thin wall type. The safety needle is not included

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/Injection-Related Reactions [see Warnings and Precautions (5.3) ] The most common adverse reactions (≥ 10%) in patients with gMG treated with efgartigimod alfa-fcab were respiratory tract infections, headache, and urinary tract infection. Injection site reactions were common (≥ 15%) in patients with gMG and CIDP who were treated with VYVGART HYTRULO ( 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. Clinical Experience in Patients with gMG The safety of efgartigimod alfa in patients with gMG was established in a double blinded placebo-controlled study with efgartigimod alfa-fcab administered intravenously (Study 1) and its open-label extension, and in an active-controlled study of VYVGART HYTRULO administered subcutaneously (Study 2) and its open-label extension [see Clinical Studies (14.1) ]. Adverse Reactions with Efgartigimod Alfa-fcab Intravenous in Patients with gMG In clinical studies, the safety of efgartigimod alfa-fcab administered intravenously has been evaluated in 246 patients with gMG who received at least one dose of efgartigimod alfa-fcab, 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 efgartigimod alfa-fcab 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, efgartigimod alfa-fcab-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 efgartigimod alfa-fcab-treated patients. Adverse reactions reported in at least 5% of patients treated with efgartigimod alfa-fcab and more frequently than placebo are summarized in Table 1. The most common adverse reactions (reported in at least 10% of efgartigimod alfa-fcab-treated patients) were respiratory tract infection, headache, and urinary tract infection. Table 1: Adverse Reactions in at least 5% of Patients with gMG Treated with Efgartigimod Alfa-fcab Intravenously (EFG IV) and More Frequently than in Placebo-Treated Patients in Study 1 (Safety Population) Adverse reaction EFG IV (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 Paresthesia 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. Adverse Reactions with VYVGART HYTRULO in Patients with gMG In an active-controlled study in patients with gMG (Study 2), 110 patients were randomized and received one cycle of once weekly administrations for 4 weeks (4 administrations total), of either VYVGART HYTRULO subcutaneously (n=55) or efgartigimod alfa-fcab intravenously (n=55) at recommended doses [see Dosage and Administration (2.2) ] . The open-label extension of Study 2 included some patients who switched from efgartigimod alfa-fcab IV to VYVGART HYTRULO. The most common adverse reactions (reported in at least 10% of VYVGART HYTRULO-treated patients) were injection site reactions and headache. In Study 2, injection site reactions occurred in 38% of patients receiving VYVGART HYTRULO. These were injection site rash, erythema, pruritus, bruising, pain, and urticaria. In Study 2 and its open-label extension (n = 168), all injection site reactions were mild to moderate in severity and did not lead to treatment discontinuation. The majority occurred within 24 hours after administration and resolved spontaneously. Most injection site reactions occurred during the first treatment cycle, and the incidence decreased with each subsequent cycle. Clinical Experience in Patients with CIDP

7 DRUG INTERACTIONS Closely monitor for reduced effectiveness of medications that bind to the human neonatal Fc receptor. When concomitant long-term use of such medications is essential for patient care, consider discontinuing VYVGART HYTRULO and using alternative therapies. ( 7 ) 7.1 Effect of VYVGART HYTRULO on Other Drugs Concomitant use of VYVGART HYTRULO with medications that bind to the human neonatal Fc receptor (FcRn) (e.g., immunoglobulin products, monoclonal antibodies, or antibody derivates containing the human Fc domain of the IgG subclass) may lower systemic exposures and reduce effectiveness of such medications. Closely monitor for reduced effectiveness of medications that bind to the human neonatal Fc receptor. When concomitant long-term use of such medications is essential for patient care, consider discontinuing VYVGART HYTRULO and using alternative therapies.