argenx Reports Positive Topline Data from ADHERE Study of VYVGART Hytrulo in Patients with Chronic Inflammatory Demyelinating Polyneuropathy - Study met primary endpoint (p=0.000039); VYVGART Hytrulo demonstrated 61% red

argenx Reports Positive Topline Data from ADHERE

Study of VYVGART Hytrulo in Patients with Chronic Inflammatory Demyelinating Polyneuropathy

endpoint (p=0.000039); VYVGART Hytrulo demonstrated 61% reduction (HR: 0.39 95% CI: 0.25; 0.61) in risk of relapse versus

- IgG autoantibodies

shown to play significant role in underlying CIDP disease biology

safety and tolerability profile consistent with previous clinical trials and confirmed safety profile of VYVGART

scheduled for today, July 17, 2023 at 8:30am ET (2:30pm CET)

Regulated information - Inside information

Amsterdam, The Netherlands - July 17,

2023 01:00 ET - argenx SE (Euronext & Nasdaq: ARGX), a global immunology company committed to improving the lives

of people suffering from severe autoimmune diseases, today announced positive topline results from the ADHERE study evaluating

VYVGART Hytrulo (efgartigimod alfa and hyaluronidase-qvfc) in adults with chronic inflammatory demyelinating polyneuropathy (CIDP).

The study met its primary endpoint (p=0.000039), demonstrating a significantly lower risk of relapse with VYVGART Hytrulo compared

to placebo. Detailed data from ADHERE will be presented at an upcoming medical meeting.

"CIDP is a chronic, progressive autoimmune disease that can cause

substantial disability in those affected, often leading to impaired ambulation or difficulty completing normal daily tasks without help.

The positive ADHERE data show that VYVGART Hytrulo may represent a new patient-forward treatment option that can prevent symptom deterioration

while minimizing side effects and treatment burden," commented Jeffrey Allen, M.D., Associate Professor, Department of Neurology,

University of Minnesota. "With ADHERE, argenx has set a new standard for innovative CIDP studies that more broadly inform the neuromuscular

community. The findings from the trial indicate we may have a novel weapon to combat this debilitating condition in our ongoing efforts

to improve the lives of individuals affected by CIDP."

"People living with CIDP often experience

significant challenges with daily function including fatigue, numbness, tingling, pain and weakness while facing a future with limited

mobility or independence. The promising ADHERE data bring hope to the CIDP community of a brighter future where they could experience

more positive moments doing the things that make them most happy," said Lisa Butler, Executive Director of the GBS-CIDP Foundation

"With these positive ADHERE data, we have

generated strong clinical evidence that CIDP has a significant IgG-driven pathogenesis component and that VYVGART Hytrulo can meaningfully

improve and stabilize disease symptoms with a favorable safety profile and a simple route of administration," commented Luc Truyen,

M.D., Ph.D., Chief Medical Officer of argenx. "We are very grateful to the patients participating in the ADHERE trial and their

supporters, the investigators, our collaborators and our argenx colleagues for the success of this innovative trial. Together, we are

moving one step closer to transforming the treatment of autoimmunity."

Detailed ADHERE Results

ADHERE is the largest clinical trial of CIDP patients

to date, enrolling adults who were treatment na ve (not on active treatment within the past six months) or currently on immunoglobulin

therapy or corticosteroids. The trial consisted of a run-in period where current treatment was stopped followed by an open-label Stage

A, after which responders to VYVGART Hytrulo advanced to a randomized, placebo-controlled Stage B.

322 patients enrolled in Stage A and received

treatment with VYVGART Hytrulo

221 responders from Stage A entered Stage B, where

the primary endpoint was the relative risk of relapse based on time to relapse on the INCAT Disability Score

VYVGART Hytrulo was well-tolerated with a safety

profile that is consistent with prior clinical trials and the known profile of VYVGART. The most frequent treatment-related adverse event

was injection site reactions (ISRs), which occurred in a lower percentage of patients than previous VYVGART Hytrulo trials (20% in Stage

A; 10% in Stage B). All ISRs were mild to moderate and resolved over time.

Conference Call Details

argenx will host a conference call today at 2:30pm CET (8:30am ET) to discuss the ADHERE results. A webcast of the live call and replay may be accessed on the Investors section of the

Please dial in 15 minutes prior to the live

About ADHERE Trial Design

The ADHERE trial was a multicenter,

randomized, double-blind, placebo-controlled trial evaluating VYVGART Hytrulo (efgartigimod alfa and

hyaluronidase-qvfc) for the treatment of chronic inflammatory demyelinating polyneuropathy (CIDP). ADHERE enrolled 322 adult

patients with CIDP who were treatment na ve (not on active treatment within the past six months or newly diagnosed) or being

treated with immunoglobulin therapy or corticosteroids. The trial consisted of an open-label Stage A followed by a randomized,

placebo-controlled Stage B. In order to be eligible for the trial, the diagnosis of CIDP was confirmed by an independent panel of

experts. Patients entered a run-in stage, where any ongoing CIDP treatment was stopped and in order to be eligible for Stage A had

to demonstrate active disease, with clinically meaningful worsening on at least one CIDP clinical assessment tool, including

INCAT, I-RODS, or mean grip strength. Treatment na ve patients were able to skip the run-in period with proof of recent

worsening. To advance to Stage B, patients needed to demonstrate evidence of clinical improvement (ECI) with VYVGART Hytrulo. ECI

was achieved through improvement of the INCAT score, or improvement on I-RODS or mean grip strength if those scales had demonstrated

worsening during the run-in period. In Stage B, patients were randomized to either VYVGART Hytrulo or placebo for up to 48 weeks.

The primary endpoint was measured once 88 total relapses or events were achieved in Stage B and was based on the hazard ratio for

the time to first adjusted INCAT deterioration (i.e. relapse). After Stage B, all patients had the option to roll-over to an

open-label extension study to receive VYVGART Hytrulo.

argenx has an exclusive license agreement with

Zai Lab for the development and commercialization of VYVGART and VYVGART Hytrulo in Greater China. Through this agreement, Zai Lab recruited

Chinese patients into the ADHERE trial.

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.

About VYVGART Hytrulo

VYVGART Hytrulo is a subcutaneous combination

of efgartigimod alfa, a human IgG1 antibody fragment marketed for intravenous use as VYVGART , and recombinant human hyaluronidase

PH20 (rHuPH20), Halozyme's ENHANZE drug delivery technology to facilitate

subcutaneous injection delivery of biologics. In binding to the neonatal Fc receptor (FcRn), VYVGART Hytrulo results in the reduction

of circulating IgG. It is the first-and-only approved FcRn blocker administered by subcutaneous injection.

VYVGART Hytrulo is the proprietary name in the

U.S. for subcutaneous efgartigimod alfa and recombinant human hyaluronidase PH20. It may be marketed under different proprietary names

following approval in other regions.

See Important Safety Information below and full

Prescribing Information for VYVGART Hytrulo for additional information

Important Safety Information

What is VYVGART 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

What is the most important information I should

know about VYVGART HYTRULO?

VYVGART HYTRULO may cause serious side effects,

Before taking VYVGART HYTRULO, tell your healthcare

provider about all of your medical conditions, including if you:

Tell your healthcare provider about all the medicines

you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

What are the common side effects of VYVGART