argenx Highlights Data Evaluating VYVGART in Neuromuscular Autoimmune Disease at AANEM and MGFA Scientific Sessions Long-term clinical trial and real-world data illustrate VYVGART drives consistent, repeatable and clinic

argenx Highlights Data Evaluating VYVGART in

Neuromuscular Autoimmune Disease at AANEM and MGFA Scientific Sessions

Long-term clinical trial and real-world data

illustrate VYVGART drives consistent, repeatable and clinically meaningful responses, including minimal symptom

expression (MSE) in generalized myasthenia gravis (gMG)

Patients treated with VYVGART experienced consistent

improvements on key quality of life measures based on long-term gMG extension data

Data across multiple indications and dosing

schedules confirm favorable safety profile and no increase in treatment-emergent adverse event rates with longer exposure

Amsterdam, the Netherlands - Nov. 1,

2023 - argenx SE (Euronext & Nasdaq: ARGX), a global immunology company committed to improving the lives of people suffering

from severe autoimmune diseases, today announced 20 presentations of clinical trial and real-world data from studies of VYVGART

and VYVGART Hytrulo (VYVGART) in neuromuscular autoimmune disease. The data presentations will be featured at the

American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM) Annual Meeting and the Myasthenia Gravis Foundation of America

(MGFA) Scientific Session, taking place in Phoenix, AZ from November 1-4, 2023.

"As leaders in the field of FcRn inhibition, we continue to generate

deep and broad data from our clinical trials, including long-term extension and real-world evidence studies," said Luc Truyen, M.D.,

Ph.D., Chief Medical Officer at argenx. "With VYVGART for gMG, we continue to show favorable safety and consistent, repeatable clinically

meaningful responses, including the ability of patients to achieve MSE, across three years of treatment. The ADHERE study, the largest

in the history of CIDP, further demonstrates our commitment to the neuromuscular community. These data characterize the broad impact our

first-in-class FcRn blocker can have on the lives of people living with CIDP, and our work to establish its safety and efficacy in the

treatment of CIDP represents an exciting step forward for this community."

Highlights from Data Presented at AANEM and

Additional data are being presented from case

studies of gMG patients with LRP4 antibodies, a meta-analysis of quality-of-life outcomes of VYVGART and other gMG treatments, and argenx-sponsored

health economic outcomes research studies demonstrating gMG patients facing social-determinants of health challenges experience health

inequities related to increased utilization of acute care facilities, and delayed diagnosis and access to treatment.

AANEM Poster Presentations (November 1-4, 2023)

MGFA Oral and Poster Presentations (November 1, 2023)

More information on the programs are available at AANEM

See Important Safety Information below and

full Prescribing Information for VYVGART Hytrulo for additional information

Important Safety Information

Hytrulo (efgartigimod alfa and hyaluronidase-qvfc)?

VYVGART Hytrulo is a

prescription medicine used to treat a condition called generalized myasthenia gravis, which causes muscles to tire and weaken easily throughout

the body, in adults who are positive for antibodies directed toward a protein called acetylcholine receptor (anti-AChR antibody positive).

IMPORTANT SAFETY INFORMATION

VYVGART and VYVGART HYTRULO

may increase the risk of infection. The most common infections observed in Study 1 were urinary tract infection (10% of efgartigimod alfa-fcab-treated

patients vs 5% of placebo-treated patients) and respiratory tract infection (33% of efgartigimod alfa-fcab-treated patients vs 29% of

placebo-treated patients). Patients on efgartigimod alfa-fcab vs placebo had below normal levels for white blood cell counts (12% vs 5%,

respectively), lymphocyte counts (28% vs 19%, respectively), and neutrophil counts (13% vs 6%, respectively). The majority of infections

and hematologic abnormalities were mild to moderate in severity. Delay the administration of VYVGART or VYVGART HYTRULO in patients with

an active infection until the infection has resolved; monitor for clinical signs and symptoms of infections. If serious infection occurs,

administer appropriate treatment and consider withholding treatment with VYVGART or VYVGART HYTRULO until the infection has resolved.

Immunization with vaccines

during treatment with VYVGART or VYVGART HYTRULO has not been studied; the safety with live or live-attenuated vaccines and the response

to immunization with any vaccine are unknown. Because VYVGART and VYVGART HYTRULO cause a reduction in immunoglobulin G (IgG) levels,

vaccination with live-attenuated or live vaccines is not recommended during treatment with VYVGART or VYVGART HYTRULO. Evaluate the need

to administer age-appropriate vaccines according to immunization guidelines before initiation of a new treatment cycle with VYVGART or

Hypersensitivity Reactions

Hypersensitivity reactions,

including rash, angioedema, and dyspnea were observed in patients treated with VYVGART or VYVGART HYTRULO. Urticaria was also observed

in patients treated with VYVGART HYTRULO. In clinical trials, hypersensitivity reactions were mild or moderate, occurred within 1 hour

to 3 weeks of administration, and did not lead to treatment discontinuation. Monitor patients during and for one hour after VYVGART administration,

or for at least 30 minutes after VYVGART HYTRULO administration, for clinical signs and symptoms of hypersensitivity reactions. If a hypersensitivity

reaction occurs during VYVGART or VYVGART HYTRULO administration, discontinue use and institute appropriate supportive measures if needed.

In Study 1, the most

common ( 10%) adverse reactions in efgartigimod alfa-fcab-treated patients were respiratory tract infection, headache, and urinary

tract infection. In Study 2, the most common ( 10%) adverse reactions in VYVGART HYTRULO-treated patients were injection site reactions

and headache. Injection site reactions occurred in 38% of VYVGART HYTRULO-treated patients, including injection site rash, erythema, pruritus,

bruising, pain, and urticaria. In Study 2 and its open-label extension, 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.

USE IN SPECIFIC POPULATIONS

As VYVGART and VYVGART

HYTRULO are expected to reduce maternal IgG antibody levels, reduction in passive protection to the newborn is anticipated. Risks and

benefits should be considered prior to administering live or live attenuated vaccines to infants exposed to VYVGART or VYVGART HYTRULO

There is no information

regarding the presence of efgartigimod alfa-fcab from administration of VYVGART, or efgartigimod alfa or hyaluronidase from administration

of VYVGART HYTRULO, in human milk, the effects on the breastfed infant, or the effects on milk production. The developmental and health

benefits of breastfeeding should be considered along with the mother's clinical need for VYVGART or VYVGART HYTRULO, and any potential

adverse effects on the breastfed infant from VYVGART or VYVGART HYTRULO or from the underlying maternal condition.

VYVGART (efgartigimod

alfa-fcab) for intravenous infusion and VYVGART HYTRULO (efgartigimod alfa and hyaluronidase-qvfc) for subcutaneous

injection are each indicated for the treatment of generalized myasthenia gravis in adult patients who are anti-acetylcholine receptor

(AChR) antibody positive.

Please see the full Prescribing

Information for VYVGART and the full Prescribing Information for VYVGART HYTRULO.

Generalized myasthenia gravis (gMG) is a rare

and chronic autoimmune disease where IgG autoantibodies disrupt communication between nerves and muscles, causing debilitating and potentially

life-threatening muscle weakness. Approximately 85% of people with MG progress to gMG within 24 months,1 where muscles throughout

the body may be affected. Patients with confirmed AChR antibodies account for approximately 85% of the total gMG population.1

About Chronic Inflammatory Demyelinating Polyneuropathy

Chronic inflammatory

demyelinating polyneuropathy (CIDP) is a rare and serious autoimmune disease of the peripheral nervous system. Although confirmation of

disease pathophysiology is still emerging, there is increasing evidence that IgG antibodies play a key role in the damage to the peripheral

nerves. People with CIDP experience fatigue, muscle weakness and a loss of feeling in their arms and legs that can get worse over time

or may come and go. These symptoms can significantly impair a person's ability to function in their daily lives. Without treatment, one-third

of people living with CIDP will need a wheelchair.

VYVGART is a human IgG1

antibody fragment that binds to the neonatal Fc receptor (FcRn), resulting in the reduction of circulating IgG autoantibodies. It is the

first approved FcRn blocker in the United States, EU and China for the treatment of adults with generalized myasthenia gravis (gMG) who

are anti- acetylcholine receptor (AChR) antibody positive and in Japan for the treatment of adults with gMG who do not have sufficient

response to steroids or non-steroidal immunosuppressive therapies (ISTs).

VYVGART Hytrulo is a