6-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the Month of May 2020

Commission File Number: 001-38097

ARGENX SE

(Translation of registrant’s name into English)

Willemstraat 5
4811 AH, Breda, the Netherlands

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F  x     Form 40-F  ¨

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): ¨

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): ¨

EXPLANATORY NOTE

On May 26, 2020, argenx SE (the “Company”) issued a press release, a copy of which is furnished hereto as Exhibit 99.1, and an investor presentation, a copy of which is filed hereto as Exhibit 99.2.

The information contained in Exhibit 99.2 to this Current Report on Form 6-K is incorporated by reference into the Company’s Registration Statements on Forms F-3 (File No. 333-225370) and S-8 (File No. 333-225375). The information contained in Exhibit 99.1 to this Current Report on Form 6-K shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended (the “Securities Act”), and shall not be incorporated by reference into any filing under the Securities Act or the Exchange Act, regardless of the general incorporation language of such filing, except as shall be expressly set forth by specific reference in such filing.

Exhibit	Description
99.1	Press Release, dated May 26, 2020
99.2	Investor Presentation, dated May 26, 2020

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

	ARGENX SE
Date: May 26, 2020	By:	/s/ Dirk Beeusaert
		Dirk Beeusaert
		General Counsel

EX-99.1

Exhibit 99.1

 

Regulated information – Inside information

argenx Announces Positive Topline Results from Phase 3 ADAPT Trial of
Efgartigimod in Patients with Generalized Myasthenia Gravis

-     Trial met primary endpoint (p ˂0.0001)

-     Well-tolerated; safety profile comparable to placebo

-     Biologics License Application on track to be submitted to U.S. Food and Drug Administration by end of 2020

-     Conference call scheduled for today, May 26, 2020 at 8:30 a.m. EDT (2:30 p.m. CEST)

May 26, 2020

Breda, the Netherlands / Ghent, Belgium – argenx (Euronext & Nasdaq: ARGX), a global immunology company committed to improving the lives of people suffering from severe autoimmune diseases and cancer, today announced positive topline data from the pivotal ADAPT trial of efgartigimod. ADAPT met its primary endpoint defined as percentage of responders on the Myasthenia Gravis Activities of Daily Living (MG-ADL) score among acetylcholine receptor-antibody positive (AChR-Ab+) generalized myasthenia gravis (gMG) patients. Responders are defined as having at least a two-point improvement on the MG-ADL score for at least four consecutive weeks. Based on these results, argenx plans to submit a Biologics License Application (BLA) to the U.S. Food and Drug Administration (FDA) by the end of 2020.

Highlights of topline ADAPT data

· 67.7% of AChR-Ab+ patients treated with efgartigimod achieved the primary endpoint compared with 29.7% on placebo (p<0.0001).

· 63.1% of AChR-Ab+ patients responded to efgartigimod compared with 14.1% on placebo on the Quantitative Myasthenia Gravis (QMG) score (p<0.0001); responder defined as having at least a three-point improvement on the QMG score for at least four consecutive weeks.

· 40.0% of efgartigimod-treated AChR-Ab+ patients achieved minimal symptom expression defined as MG-ADL scores of 0 (symptom free) or 1, compared to 11.1% treated with placebo.

· Efgartigimod was well-tolerated with a safety profile that was comparable to placebo.

“The efgartigimod data showed rapid and robust responses in people with gMG, as well as a favorable tolerability profile,” said James F. Howard Jr., M.D., Professor of Neurology (Neuromuscular Disease), Medicine and Allied Health, Department of Neurology, The University of North Carolina at Chapel Hill School of Medicine and principal investigator for the ADAPT trial. “Patients with this devastating disease can experience chronic and potentially life-threatening muscle weakness that has a major impact on their quality of life, and more treatment options are needed. These data are very encouraging as they show efgartigimod has potential to make a meaningful impact on daily living activities, and we are hopeful they will lead to a new treatment being available for the gMG community.”

“With the ADAPT trial, we set out to evaluate efgartigimod’s ability to redefine the treatment paradigm for people living with gMG. The data showed that efgartigimod drove fast and deep responses, including in a proportion of patients who achieved minimal or no symptoms after treatment. In addition, we saw responses that lasted beyond eight or 12 weeks, supporting our plans to offer individualized dosing schedules that are purpose-fit to the variability in disease course that gMG patients experience,” commented Wim Parys, M.D., Chief Medical Officer of argenx. “Based on these data, we intend to submit a BLA for efgartigimod to the FDA before the end of the year, taking us one step closer to potentially making efgartigimod available to patients in 2021. All of us at argenx want to thank the patients and healthcare providers who participated in the ADAPT trial. ADAPT is the first pivotal trial of efgartigimod and these data further our confidence in its broad opportunity in other severe, IgG-mediated autoimmune diseases.”

Additional ADAPT results, including secondary endpoints and prespecified analyses

· In the ADAPT trial, the secondary endpoints listed below also demonstrated statistically significant differences in the efgartigimod arm for AChR-Ab+ patients, unless otherwise noted, compared to placebo:

o MG-ADL responders in the overall population, including both AChR-Ab+ and AChR-antibody negative patients (p<0.0001).

o Time on trial in clinically meaningful improvement (MG-ADL improvement ≥2) (p=0.0001).

o Fast onset of response on MG-ADL score (onset observed in first two weeks) (p=0.0004).

o Time to qualify for retreatment endpoint did not meet statistical significance.

· In AChR-Ab+ patients who met the primary endpoint, the majority showed a sustained response, including 88.6% who achieved a response for at least six weeks, 56.8% for at least eight weeks and 34.1% for at least 12 weeks.

· Of AChR-Ab+ patients who received a second treatment cycle, 70.6% were MG-ADL responders compared to 25.6% of placebo patients.

· 90% of patients enrolled in the ADAPT trial continued to the ADAPT-Plus open-label extension study.

· Percentage of efgartigimod responders on the MG-ADL score in the AChR-antibody negative patient population was consistent with the AChR-Ab+ patient population, but a greater placebo response was observed in this cohort.

Detailed data from the ADAPT trial will be submitted for presentation at a future medical meeting.

Phase 3 ADAPT Trial Design

The Phase 3 ADAPT trial was a randomized, double-blind, placebo-controlled, multi-center, global trial evaluating the safety and efficacy of efgartigimod in patients with gMG. A total of 167 adult patients with gMG in North America, Europe and Japan enrolled in the trial and were treated. Enrolled patients had a confirmed gMG diagnosis and an MG-ADL total score of five or greater. Patients were on a stable dose of at least one gMG treatment prior to randomization, including acetylcholinesterase inhibitors, corticosteroids or nonsteroidal immunosuppressive drugs, and were required to remain on that stable dose throughout the primary trial. Patients were eligible to enroll in ADAPT regardless of antibody status, including patients with AChR antibodies (AChR-Ab+) and patients where AChR antibodies were not detected. 

Patients were randomized in a 1:1 ratio to receive efgartigimod or placebo for a total of 26 weeks as part of the primary trial. ADAPT was designed to enable an individualized treatment approach with an initial treatment cycle followed by a variable number of subsequent treatment cycles. Treatment cycles consist of four infusions of efgartigimod (10mg/kg IV) or placebo at weekly intervals. Retreatment with additional treatment cycles was initiated according to clinical response. The primary endpoint was the number of AChR-Ab+ patients who achieved a response on the MG-ADL score defined by at least a two-point improvement for four or more consecutive weeks.

After the 26-week primary ADAPT trial, patients were eligible to roll-over into an open-label extension, ADAPT Plus. 

About Efgartigimod

Efgartigimod is a first-in-class antibody fragment designed to reduce disease-causing immunoglobulin G (IgG) antibodies and block the IgG recycling process. Efgartigimod binds to the neonatal Fc receptor (FcRn), which is widely expressed throughout the body and plays a central role in rescuing IgG antibodies from degradation. Blocking FcRn reduces IgG antibody levels representing a logical potential therapeutic approach for several autoimmune diseases known to be driven by disease-causing IgG antibodies, including: myasthenia gravis (MG), a chronic disease that causes muscle weakness; pemphigus vulgaris (PV), a chronic disease characterized by severe blistering of the skin; immune thrombocytopenia (ITP), a chronic bruising and bleeding disease; and chronic inflammatory demyelinating polyneuropathy (CIDP), a neurological disease leading to impaired motor function.

About Myasthenia Gravis (MG)

MG is a rare and chronic autoimmune disease where IgG antibodies disrupt communication between nerves and muscles, causing debilitating and potentially life-threatening muscle weakness. More than 85% of people with MG progress to generalized MG (gMG) within 18 months, where muscles throughout the body may be affected, resulting in extreme fatigue and difficulties with facial expression, speech, swallowing and mobility. In more life-threatening cases, MG can affect the muscles responsible for breathing. Patients with confirmed AChR antibodies account for 80-90% of the total gMG population. There are approximately 65,000 people in the United States and 20,000 people in Japan living with the disease.

Conference Call Details

Management will host a conference call and webcast presentation today at 2:30 p.m. Central European Summer Time (CEST) / 8:30 a.m. Eastern Daylight Time (EDT). To participate in the conference call, please select your phone number below and use the confirmation code 6295982. The webcast may be accessed on the Investors page of the argenx website at www.argenx.com or by clicking here.

Dial-in numbers:

Please dial in 5–10 minutes prior to 2:30 p.m. CEST / 8:30 a.m. EDT using the number and conference ID below.

Confirmation Code: 6295982

Belgium: +32 (0)2 793 3847

Belgium: 0800 484 71

France:+33 (0)1 7070 0781

France:0805 101 465

Netherlands: +31 (0)2 0795 6614

Netherlands: 0800 023 5015

UK: +44 (0) 844 481 9752

UK: 0800 279 6619

US: +1646 741 3167

US: 1877 870 9135

About argenx

argenx is a global immunology company committed to improving the lives of people suffering from severe autoimmune diseases and cancer. Partnering with leading academic researchers through its Immunology Innovation Program (IIP), argenx is translating immunology breakthroughs into a world-class portfolio of novel antibody-based medicines. argenx is evaluating efgartigimod in multiple serious autoimmune diseases, and cusatuzumab in hematological cancers in collaboration with Janssen. argenx is also advancing several earlier stage experimental medicines within its therapeutic franchises. argenx has offices in Belgium, the United States and Japan. For more information, visit www.argenx.com and follow us on LinkedIn at https://www.linkedin.com/company/argenx/.

Contacts:

Beth DelGiacco, Vice President, Investor Relations (US)

+1 518 424 4980

bdelgiacco@argenx.com

Joke Comijn, Director Corporate Communications & Investor Relations (EU)

+32 (0)477 77 29 44

+32 (0)9 310 34 19

JComijn@argenx.com

Forward-looking Statements

The contents of this announcement include statements that are, or may be deemed to be, “forward-looking statements.” These forward-looking statements can be identified by the use of forward-looking terminology, including the terms “believes,” “estimates,” “anticipates,” “expects,” “intends,” “may,” “will,” or “should” and include statements argenx makes concerning the safety, tolerability and efficacy of efgartigimod and the results of the ADAPT trial; the timing of planned regulatory submissions with the FDA and, if approved, launch in the U.S.; the therapeutic and commercial potential of efgartigimod; the opportunity of efgartigimod in other severe, IgG-mediated autoimmune diseases; and the intended results of its strategy. By their nature, forward-looking statements involve risks and uncertainties and readers are cautioned that any such forward-looking statements are not guarantees of future performance. argenx’s actual results may differ materially from those predicted by the forward-looking statements as a result of various important factors, including argenx’s expectations regarding its the inherent uncertainties associated with competitive developments, preclinical and clinical trial and product development activities and regulatory approval requirements; failure to demonstrate the safety, tolerability and efficacy of argenx’s product candidates; final and quality controlled verification of data and the related analyses; the expense and uncertainty of obtaining regulatory approval, including from the U.S. Food and Drug Administration and European Medicines Agency; the possibility of having to conduct additional clinical trials; argenx’s reliance on collaborations with third parties; estimating the commercial potential of argenx’s product candidates; argenx’s ability to obtain and maintain protection of intellectual property for its technologies and drugs; argenx’s limited operating history; and argenx’s ability to obtain additional funding for operations and to complete the development and commercialization of its product candidates. A further list and description of these risks, uncertainties and other risks can be found in argenx’s U.S. Securities and Exchange Commission (SEC) filings and reports, including in argenx’s most recent annual report on Form 20-F filed with the SEC as well as subsequent filings and reports filed by argenx with the SEC. Given these uncertainties, the reader is advised not to place any undue reliance on such forward-looking statements. These forward-looking statements speak only as of the date of publication of this document. argenx undertakes no obligation to publicly update or revise the information in this press release, including any forward-looking statements, except as may be required by law.

EX-99.2

Exhibit 99.2

26 May 2020 ADAPT Phase 3 Topline R esults Efgartigimod in Generalized Myasthenia Gravis

Forward - Looking Statements Safe Harbor: Certain statements contained in this presentation, other than present and historical facts and conditions independently verifiable at the date hereof, may constitute forward - looking statements. Examples of such forward - looking statements include those regarding our investigational product candidates and preclinical studies and clinical trials, and the status, the safety, tolerability and efficacy of efgartigimod and the results of the ADAPT trial; the timing of presentation of detailed results from the ADAPT trial, planned regulatory submissions with the FDA and PSMA and, if approved, launch in the U.S.; and the therapeutic and commercial potential of efgartigimod, as well as those regarding plans, timing of expected data readouts and related presentations and related results thereof, including the design of our trials and the availability of data from them, the timing and achievement of our product candidate development activities, our ability to obtain regulatory approval of our product candidates, the expected size of the markets for our product candidates, future results of operations and financial positions, including potential milestones, business strategy, plans and our objectives for future operations. When used in this presentation, the words “anticipate,” “believe,” “can,” “could,” “estimate,” “expect,” “intend,” “is designed to,” “may,” “might,” “will,” “plan,” “potential,” “predict,” “objective,” “should,” or the negative of these and similar expressions identify forward - looking statements. Such statements, based as they are on the current analysis and expectations of management, inherently involve numerous risks and uncertainties, known and unknown, many of which are beyond the Company’s control. Such risks include, but are not limited to: the impact of the COVID - 19 pandemic on our business, the impact of general economic conditions, general conditions in the biopharmaceutical industries, changes in the global and regional regulatory environments in the jurisdictions in which the Company does or plans to do business, market volatility, fluctuations in costs and changes to the competitive environment. Consequently, actual future results may differ materially from the anticipated results expressed in the forward - looking statements. In the case of forward - looking statements regarding investigational product candidates and continuing further development efforts, specific risks which could cause actual results to differ materially from the Company’s current analysis and expectations include: failure to demonstrate the safety, tolerability and efficacy of our product candidates; final and quality controlled verification of data and the related analyses; the expense and uncertainty of obtaining regulatory approval, including from the U.S. Food and Drug Administration and European Medicines Agency; the possibility of having to conduct additional clinical trials; our ability to obtain and maintain intellectual property protection for our product candidates; and our reliance on third parties such as our licensors and collaboration partners regarding our suite of technologies and product candidates. Further, even if regulatory approval is obtained, biopharmaceutical products are generally subject to stringent on - going governmental regulation, challenges in gaining market acceptance and competition. These statements are also subject to a number of material risks and uncertainties that are described in the Company’s filings with the U.S. Securities and Exchange Commission (“SEC”), including in argenx’s most recent annual report on Form 20 - F filed with the SEC as well as subsequent filings and reports filed by argenx with the SEC . The reader should not place undue reliance on any forward - looking statements included in this presentation. These statements speak only as of the date made and the Company is under no obligation and disavows any obligation to update or revise such statements as a result of any event, circumstances or otherwise, unless required by applicable legislation. This presentation has been prepared by argenx se (“ argenx ” or the “company”) for informational purposes only and not for any other purpose. Nothing contained in this presentation is, or should be construed as, a recommendation, promise or representation by the presenter or the company or any director, employee , a gent, or adviser of the company. This presentation does not purport to be all - inclusive or to contain all of the information you may desire. This presentation also contains estimates and o ther statistical data made by independent parties and by us relating to market size and growth and other data about our industry. This data involves a number of assumptions and limitations, and you are cautioned not to give undue weight to such estimates. ! 2

Efgartigimod Showed Robust Benefit For Patients With gMG • Statistically significant and clinically meaningful improvement in MG - ADL • Fast and deep responses • Potential for individualized dosing • Safety & tolerability profile comparable to placebo Primary endpoint met Meaningful patient benefit observed Favorable tolerability observed 3

gMG is a Chronic and Debilitating Autoimmune Disease “Severe & generalized muscle weakness” Symptoms of Generalized Myasthenia Gravis Diplopia Difficulty speaking Ptosis Difficulty swallowing Respiratory impairment Loss of motor skills Impaired mobility Extreme fatigue High need for safe & efficacious medication Up to 20% of patients experience a life - threatening myasthenic crisis (severe respiratory failure) 85% of people with MG progress* to generalized MG within 18 months *Progression to gMG may be less with early immunosuppressive treatment 1. Grob et al. Muscle Nerve 2008;37:141 - 9; 2. Jacob. Eur Neurol Rev 2018;13:18−20; 3. Wendell. Neurohospitalist 2011;1:16 – 22, 4. Gilhus . N Engl J Med 2016;375:2570 - 81 4

IgG Auto - Antibodies Drive Myasthenia Gravis Efgartigimod is Designed to Eliminate Auto - Antibodies Block acetylcholine receptors ( AChR ) Crosslink + internalize ACh Rs AChR auto - antibodies in MG 1 2 Recruit complement 3 Other auto - antibodies in MG ( MuSK , LRP4, other/unknown) Block function of auto - antibody target 1 5

Innovative ADAPT Trial Designed With the Patient in Mind Primary endpoint: % MG - ADL responders (≥ 2 - point improvement for at least four consecutive weeks during the first cycle in AChR - Ab+ patients) Retreatment criteria were protocol defined based on loss of clinically meaningful improvement 151 patients (90%) rolled over to the Open Label Extension Study Patient population Individualized treatment over 26 weeks 167 gMG patients (MG - ADL≥5) Stratification • ethnicity • background therapy • auto - antibody type Efgartigimod 10mg/kg IV or placebo …….. 1st cycle (8 weeks) …….. Primary endpoint analysis Continuation or retreatment (up to 2 additional cycles) 6

Baseline Characteristics Total patients AChR Ab+ patients Efgartigimod (N=84) Placebo (N=83) Efgartigimod (N=65) Placebo (N=64) Age Mean years (SD) 45.9 (14.4) 48.2 (15.0) 44.7 (15.0) 49.2 (15.5) Females n (%) 63 (75.0) 55 (66.3) 46 (70.8) 40 (62.5) Time since diagnosis Mean years (SD) 10.13 (9.0) 8.83 (7.6) 9.68 (8.3) 8.93 (8.2) MG - ADL score Mean (SD) 9.2 (2.6) 8.8 (2.3) 9.0 (2.5) 8.6 (2.1) QMG score Mean (SD) 16.2 (5.0) 15.5 (4.6) 16.0 (5.1) 15.2 (4.4) MGFA class at screening n (%) Class II 34 (40.5) 31 (37.3) 28 (43.1) 25 (39.1) Class III 47 (56.0) 49 (59.0) 35 (53.8) 36 (56.3) Class IV 3 (3.6) 3 (3.6) 2 (3.1) 3 (4.7) MG therapies at baseline* n (%) Any NSID 51 (60.7) 51 (61.4) 40 (61.5) 37 (57.8) No NSID 33 (39.3) 32 (38.6) 25 (38.5) 27 (42.2) AChR Ab status (n AChR Ab+ / n AChR Ab - ) 65 / 19 64 / 19 65 / 0 64 / 0 *Any Non - Steroidal Immunosuppressive Drug (NSID): Azathioprine, Cyclosporin, Cyclophosphamide, Methotrexate, Mycophenolate, Tacr olimus (in mono - or combination therapy); No NSID: any acetylcholinesterase ( AChE ) inhibitor and/or steroid (in mono - or combination therapy) 7

Favorable Tolerability Profile Efgartigimod (N=84) Placebo (N=83) Number of patients with an Adverse Event (AE) n (%) 65 (77.4) 70 (84.3) Number of patients with an AE grade ≥3 n (%) 9 (10.7) 8 (9.6) Most frequent AEs n (%) Headache 24 (28.6) 23 (27.7) Nasopharyngitis 10 (11.9) 15 (18.1) Nausea 7 (8.3) 9 (10.8) Diarrhea 6 (7.1) 9 (10.8) Upper respiratory tract infection 9 (10.7) 4 (4.8) Number of patients who discontinued due to AEs n (%) 3 (3.6) 3 (3.6) Number of patients with a Serious Adverse Event (SAE) n (%) 4 (4.8) 7 (8.4) Number of patients with AEs deemed related by investigator n (%) 26 (31.0) 22 (26.5) There were two occurrences of malignancies during the study: a rectal adenocarcinoma in Efgartigimod group and a basal cell c arc inoma in placebo group Most adverse events were considered mild or moderate; safety profile of Efgartigimod group was comparable to placebo 8

29.7% 0% 10% 20% 30% 40% 50% 60% 70% 80% Efgartigimod Placebo 67.7% N=19/64 N=44/65 MG - ADL responders ( AChR - Ab+ patients, first cycle) MG - ADL responder : ≥ 2 - point improvement for at least four consecutive weeks during the first cycle % MG - ADL responders Primary Endpoint Met: Statistically Significant and Clinically Meaningful Improvement in Daily Living Activities P < 0.0001 9

14.1% 0% 10% 20% 30% 40% 50% 60% 70% 80% Efgartigimod Placebo 63.1% N=9/64 N=41/65 QMG responders ( AChR - Ab+ patients, first cycle) QMG responder : ≥ 3 - point improvement for at least four consecutive weeks during the first cycle (Secondary endpoint) % QMG responders Statistically Significant and Clinically Meaningful Improvement in QMG Response P < 0.0001 10

11.1% 0% 10% 20% 30% 40% 50% 60% 70% 80% Efgartigimod Placebo 40.0% N=7/63 N=26/65 Minimal Symptom Expression ( AChR - Ab+ patients, first cycle) Minimal Symptom Expression: MG - ADL = 0 (no symptoms) or 1 % patients with MSE 40% of Efgartigimod Patients Achieved Minimal Symptom Expression Compared To 11% in Placebo P < 0.0001 11

Secondary Endpoints Support Benefit Other secondary Endpoints Measure Population Time Efgartigimod Placebo P - value Response QMG responder AChR Ab + First cycle 63.1% (41/65) 14.1% (9/64) <0.0001 Response MG - ADL responder AChR Ab + & AChR Ab - First cycle 67.9% (57/84) 37.3% (31/83) <0.0001 Duration % of study duration ≥ 2 - point improvement in MG - ADL AChR Ab + Until day 126* 48.7% 26.6% 0.0001 Duration Days until qualification for retreatment, measured from one week after the last infusion AChR Ab + Full study Median 35 days Median 8 days 0.2604 Onset MG - ADL responder onset within first 2 weeks AChR Ab + First cycle 56.9% (37/65) 25.0% (16/64) 0.0004 *Day 126 was the last day it was possible to start a retreatment cycle and complete within the study 12

z Fast Onset of Action Early onset MG - ADL responders ( AChR Ab+ Efgartigimod responders, first cycle) 84.1% Early onset MG - ADL responders ( AChR Ab+ patients, first cycle) Early onset responder : Onset of MG - ADL response during the first two weeks 56.9% 25.0% 0% 10% 20% 30% 40% 50% 60% 70% 80% Efgartigimod Placebo % of Early MG - ADL responders N=37/65 N=16/64 N=37/44 P = 0.0004 13

Durable Clinical Benefit Time to qualify for retreatment ( AChR Ab+ patients, full study) 35 8 0 5 10 15 20 25 30 35 40 45 Efgartigimod Placebo Median time (Days) Time to qualify for retreatment : time from one week after last infusion until no clinically meaningful improvement Duration of response ( AChR Ab+ Efgartigimod responders, first cycle) 100.0% 88.6% 56.8% 34.1% 0% 20% 40% 60% 80% 100% 4 weeks or more 6 weeks or more 8 weeks or more 12 weeks or more Responder by definition is at least 4 consecutive weeks max response: 25 weeks *P - value calculated with Log - Rank test N=44/44 N=39/44 N=25/44 N=15/44 P =0.2604* 14

Repeat Treatment Yielded Equally Strong Benefit P < 0.0001 MG - ADL responder: ≥ 2 - point improvement for at least four consecutive weeks during the first cycle 67.7% 29.7% 0% 10% 20% 30% 40% 50% 60% 70% 80% Efgartigimod Placebo 70.6% 25.6% 0% 10% 20% 30% 40% 50% 60% 70% 80% Efgartigimod Placebo % MG - ADL responders % MG - ADL response 36.8% of Efgartigimod patients not responding to 1st treatment cycle did respond in 2nd treatment cycle N=44/65 N=19/64 N=36/51 N=11/43 MG - ADL responders ( AChR - Ab+ patients, first cycle ) MG - ADL responders ( AChR - Ab+, second cycle ) P < 0.0001 P < 0.0001 15

Expected Next Steps Present detailed ADAPT results at upcoming meeting Submit BLA to FDA in H2 2020 Submit J - MAA with PMDA in H1 2021 1 2 3 Launch in the US in 2021, if approved 4 16

17 • Fast - acting steroids and slow - acting immunosuppressants • Balancing symptom suppression and side effects ADAPT Data Support MG Treatment Paradigm Shift ( 1) Subject to regulatory approval (2) Based on topline data from Adapt trial Individualized dosing Toward minimal symptom expression MG Symptoms Chronic dosing TAPER MG Symptoms Fast onset of response Deep response, 40% MSE Well tolerated New Treatment Paradigm Current Standard of Care