Efgartigimod Alfa

VYVGART is indicated for the treatment of adult patients with generalized myasthenia gravis (gMG). VYVGART is a neonatal Fc receptor blocker indicated for the treatment of adult patients with generalized myasthenia gravis (gMG). ( 1 )

Injection: 400 mg/20 mL (20 mg/mL) as a colorless to slightly yellow, clear to slightly opalescent solution, in a single-dose vial. Injection: 400 mg in 20 mL (20 mg/mL) single-dose vial. ( 3 )

VYVGART is contraindicated in patients with serious hypersensitivity to efgartigimod alfa products or to any of the excipients of VYVGART . Reactions have included anaphylaxis and hypotension leading to syncope [see Warnings and Precautions (5.2) ] . VYVGART is contraindicated in patients with serious hypersensitivity to efgartigimod alfa products or to any of the excipients of VYVGART. ( 4 )

Infections: Delay administration of VYVGART to patients with an active infection. Monitor for signs and symptoms of infection in patients treated with VYVGART. If serious infection occurs, administer appropriate treatment and consider withholding VYVGART until the infection has resolved. ( 5.1 ) Hypersensitivity Reactions: Anaphylaxis, hypotension leading to syncope, angioedema, dyspnea, and rash have occurred. If a hypersensitivity reaction occurs, the healthcare professional should institute appropriate measures if needed or the patient should seek medical attention. ( 4 , 5.2 ) Infusion-Related Reactions: If a severe infusion-related reaction occurs, discontinue the infusion and initiate appropriate therapy; consider risks and benefits of readministering. If a mild to moderate infusion-related reaction occurs, consider rechallenging with close clinical observation, slower infusion rates, and pre-medications. ( 5.3 )

5.1 Infections VYVGART may increase the risk of infection. The most common infections observed in Study 1 were urinary tract infection (10% of VYVGART-treated patients compared to 5% of placebo-treated patients) and respiratory tract infections (33% of VYVGART-treated patients compared to 29% of placebo-treated patients) [see Adverse Reactions (6.1) and Clinical Studies (14) ] . A higher frequency of patients who received VYVGART compared to placebo were observed to have below normal levels for white blood cell counts (12% versus 5%, respectively), lymphocyte counts (28% versus 19%, respectively), and neutrophil counts (13% versus 6%, respectively). The majority of infections and hematologic abnormalities were mild to moderate in severity. Delay VYVGART administration in patients with an active infection until the infection is resolved. During treatment with VYVGART, monitor for clinical signs and symptoms of infections. If serious infection occurs, administer appropriate treatment and consider withholding VYVGART until the infection has resolved. Immunization Evaluate the need to administer age-appropriate vaccines according to immunization guidelines before initiation of a new treatment cycle with VYVGART. The safety of immunization with live vaccines and the immune response to vaccination during treatment with VYVGART are unknown. Because VYVGART causes a reduction in IgG levels, vaccination with live vaccines is not recommended during treatment with VYVGART.

5.2 Hypersensitivity Reactions In clinical trials, hypersensitivity reactions, including rash, angioedema, and dyspnea were observed in VYVGART-treated patients. Hypersensitivity reactions were mild or moderate, occurred within one hour to three weeks of administration, and did not lead to treatment discontinuation. Anaphylaxis and hypotension leading to syncope have been reported in postmarketing experience with VYVGART. Anaphylaxis and hypotension occurred during or within an hour of administration and led to infusion discontinuation and in some cases to permanent treatment discontinuation. Monitor patients during administration and for 1 hour thereafter for clinical signs and symptoms of hypersensitivity reactions. If a hypersensitivity reaction occurs, the healthcare professional should institute appropriate measures if needed or the patient should seek medical attention. VYVGART is contraindicated in patients with a history of serious hypersensitivity to efgartigimod alfa products or to any of the excipients of VYVGART [see Contraindications (4) ] .

5.3 Infusion-Related Reactions Infusion-related reactions have been reported with VYVGART in postmarketing experience. The most frequent symptoms and signs were hypertension, chills, shivering, and thoracic, abdominal, and back pain. Infusion-related reactions occurred during or within an hour of administration and led to infusion discontinuation. If a severe infusion-related reaction occurs during administration, discontinue VYVGART infusion and initiate appropriate therapy. Consider the risks and benefits of readministering VYVGART following a severe infusion-related reaction. If a mild to moderate infusion-related reaction occurs, patients may be rechallenged with close clinical observation, slower infusion rates, and pre-medications.

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 in adult patients with gMG has been evaluated in 364 patients who received at least one dose of VYVGART. 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 In the placebo-controlled study in patients with gMG who are anti-acetylcholine receptor (AChR) antibody negative (Study 2), 119 patients received one cycle of once-weekly administrations for 4 weeks of either VYVGART 10 mg/kg (n=58) or placebo (n=61). The overall safety profile in Study 2 was consistent with the known safety profile of VYVGART in patients with gMG, except for nausea, which occurred in 7% of anti-AChR antibody negative patients who received VYVGART compared to 5% of patients who received placebo. The safety of initiating subsequent cycles between 7 and 28 days from the last administration of the previous treatment cycle was assessed in another study in 60 patients with gMG (78% AChR antibody positive and 22% anti-AChR antibody negative). 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) ].

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 and using alternative therapies. ( 7 )

7.1 Effect of VYVGART on Other Drugs Concomitant use of VYVGART 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 and using alternative therapies.

8.1 Pregnancy Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to VYVGART during pregnancy. Healthcare providers and patients may call 1-855-272-6524 or go to https://www.Vyvgartpregnancy.com to enroll in or to obtain information about the registry. Risk Summary There are no available data on the use of VYVGART during pregnancy. There is no evidence of adverse developmental outcomes following the administration of VYVGART at up to 100 mg/kg/day in rats and rabbits (see Data ). The background rate of major birth defects and miscarriage in the indicated population is unknown. In the U.S. general population, the estimated background rate of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Clinical Considerations Fetal/Neonatal Adverse Reactions Monoclonal antibodies are increasingly transported across the placenta as pregnancy progresses, with the largest amount transferred during the third trimester. Therefore, efgartigimod alfa-fcab may be transmitted from the mother to the developing fetus. As VYVGART is expected to reduce maternal IgG antibody levels, reduction in passive protection to the newborn is anticipated. Risk and benefits should be considered prior to administering live vaccines to infants exposed to VYVGART in utero [see Warnings and Precautions (5.1) ]. Data Animal Data Intravenous administration of efgartigimod alfa-fcab (0, 30, or 100 mg/kg/day) to pregnant rats and rabbits throughout organogenesis resulted in no adverse effects on embryofetal development in either species. The doses tested are 3 and 10 times the recommended human dose (RHD) of 10 mg/kg, on a body weight (mg/kg) basis. Intravenous administration of efgartigimod alfa-fcab (0, 30, or 100 mg/kg/day) to rats throughout gestation and lactation resulted in no adverse effects on pre- or postnatal development. The doses tested are 3 and 10 times the recommended human dose (RHD) of 10 mg/kg, on a body weight (mg/kg) basis.

8.2 Lactation Risk Summary There is no information regarding the presence of efgartigimod alfa-fcab in human milk, the effects on the breastfed infant, or the effects on milk production. Maternal IgG is known to be present in human milk. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for VYVGART and any potential adverse effects on the breastfed infant from VYVGART or from the underlying maternal condition.

8.4 Pediatric Use Safety and effectiveness in pediatric patients have not been established.

8.5 Geriatric Use Clinical studies of VYVGART did not include sufficient numbers of patients aged 65 and older to determine whether they respond differently from younger adult patients.

8.6 Renal Impairment No dose adjustment of VYVGART is needed for patients with mild renal impairment. There are insufficient data to evaluate the impact of moderate renal impairment (eGFR 30-59 mL/min/1.73 m 2 ) and severe renal impairment (eGFR <30 mL/min/1.73 m 2 ) on pharmacokinetic parameters of efgartigimod alfa-fcab [see Clinical Pharmacology (12.3) ].

Efgartigimod alfa-fcab is a human IgG1 antibody fragment that binds to the neonatal Fc receptor (FcRn), resulting in the reduction of circulating IgG.