Argenx SE 6-K, filed Oct 6, 2020

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 OF1934

For the Month of October 2020

Commission File Number: 001-38097

ARGENX SE

(Translation of registrant’s name into English)

Willemstraat5

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 October 5, 2020 and October 6, 2020, argenx SE (the “Company”) issued press releases, copies of which are attached hereto as Exhibit 99.1 and Exhibit 99.2 and are incorporated by reference herein.

The information contained in this Current Report on Form 6-K,including Exhibits 99.1 and 99.2, 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).

Exhibit	Description
99.1	Press Release dated October 5, 2020
99.2	Press Release dated October 6, 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: October 6, 2020	By:	/s/ Dirk Beeusaert
		Dirk Beeusaert
		General Counsel

Exhibit 99.1

argenx Presents Additional EfgartigimodData from Global Phase 3 ADAPT Trial

at the Myasthenia Gravis Foundation of America 2020 Scientific Session

• New data consistent with positive topline results showing rapid and clinically meaningful responses to efgartigimod and safety profile comparable to placebo

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

October 5, 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 the presentation of new data from the pivotal Phase 3 ADAPT trial evaluating efgartigimod for the treatment of patients with generalized myasthenia gravis (gMG). The presentation took place on Saturday, October 3, 2020 at the Myasthenia Gravis Foundation of America (MGFA) 2020 Virtual Scientific Session. argenx previously reported positive topline results from ADAPT in May 2020.

“Myasthenia gravis can be a very debilitating and potentially life-threatening chronic disease in patients leading to impairments that affect a patient’s ability to complete normal daily activities, including walking, swallowing, chewing food, talking or breathing easily. Efgartigimod demonstrated in ADAPT that it is well-tolerated and that patients can experience clinically meaningful improvements in key measures of function and strength following treatment, including, in some, the achievement of minimal symptom expression. These exciting results suggest that efgartigimod as a new potential therapy for gMG patients could have a real impact on some of the daily limitations that patients face,” commented 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.

Highlights of New Data Presented atMGFA 2020 Virtual Scientific Session

Magnitude of response: Substantial proportion of efgartigimod-treated acetylcholine receptor-antibody positive (AChR-Ab+) patients showed benefit at increasing thresholds on the Myasthenia Gravis Activities of Daily Living (MG-ADL) and Quantitative Myasthenia Gravis (QMG) scores compared to placebo patients at week four (one week after first treatment cycle).

·	At least half of efgartigimod-treated<br>patients showed a five-point or greater improvement on the MG-ADL score (55.6%) and a six-point or greater improvement on the QMG<br>score (50.0%)
·	One third (33.9%) of efgartigimod-treated<br>patients showed a nine-point or greater improvement on the QMG score compared to zero patients on placebo
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Repeatabilityof response: Similar proportion of efgartigimod-treated AChR-Ab+ patients were MG-ADL responders in the first (67.7% efgartigimod versus 29.7% placebo) and second (70.6% efgartigimod versus 25.6% placebo) treatment cycles (p<0.0001 for both cycles)

·	In efgartigimod-treated patients, mean<br>change from cycle baseline in total MG-ADL score at week four was 4.6 in cycle one and 5.1 in cycle two
·	78.5% (51/65) of efgartigimod-treated<br>patients were MG-ADL responders across treatment cycles one and two
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Clinicalbenefit in seronegative patients: Inclusion of QMG score in responder analysis showed further evidence of activity in patients where AChR antibodies were not detected (AChR-Ab-)

·	52.6% (10/19) of efgartigimod-treated<br>patients were responders on the QMG score compared to 36.8% (7/19) of placebo patients
·	Post-hoc analysis showed that 47.4% (9/19)<br>of efgartigimod-treated patients were responders on both the QMG and the MG-ADL scores compared to 21.1% (4/19) of placebo patients
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Key pharmacodynamicparameters: Total IgG and pathogenic autoantibody levels were reduced in efgartigimod-treated AChR-Ab+ patients throughout observation period, supporting proposed mechanism of action

·	Mean maximum reductions at week four were<br>61.3% for total IgG and 57.6% for AChR-Ab
·	Reductions similar across IgG subtypes<br>and in overall population (AChR-Ab+ and AChR-Ab-)
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·	No reduction in albumin levels
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Key Topline Data Previously Reportedfrom ADAPT

Topline data from ADAPT were reported in May 2020. The trial met its primary endpoint showing 67.7% of efgartigimod-treated AChR-Ab+ gMG patients were responders on the MG-ADL score compared to 29.7% of placebo patients (p<0.0001). Responders were defined by having at least a 2-point change on the MG-ADL for at least four consecutive weeks. Efgartigimod was demonstrated to be well-tolerated with a safety profile that was comparable to placebo.

·	63.1% of AChR-Ab+ patients were responders<br>to efgartigimod compared with 14.1% on placebo on the QMG score (p<0.0001); responder defined as having at least a three-point<br>improvement for at least four consecutive weeks.
·	40.0% of efgartigimod-treated AChR-Ab+<br>patients achieved minimal symptom expression (MG-ADL scores of 0 (symptom free) or 1) as a result of one treatment cycle, compared<br>to 11.1% treated with placebo (p<0.0001).
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·	84.1% of patients who were MG-ADL responders (37/44) had an onset of effect within the first two<br>weeks
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·	In AChR-Ab+ patients who met the primary endpoint, the majority showed a sustained response, including<br>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
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“These new data on the magnitude and repeatability of response continue to support the potential of efgartigimod as a meaningful treatment for gMG patients. ADAPT was also a broad trial which included patients with acetylcholine receptor antibodies present and those without. We were pleased to show in this presentation proof of activity in the antibody-negative patients who are often left out of clinical trials,” commented Wim Parys, M.D., Chief Medical Officer of argenx. “It is particularly gratifying to present these favorable new data at the MGFA Virtual Scientific Session, a scientific meeting solely focused on addressing unmet needs for people living with gMG. We look forward to submitting our Biologics License Application for efgartigimod to the U.S. Food and Drug Administration before the end of the year with the goal to have efgartigimod available to patients and physicians in 2021.”

Phase 3 ADAPT Trial

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. 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. ADAPT was designed to enable an individualized treatment approach with an initial treatment cycle followed by a variable number of subsequent treatment cycles. 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.

About Efgartigimod

Efgartigimod is an investigational 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.

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 aims to translate 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/.

Forward-looking Statements

The contents of this announcement include statements thatare, or may be deemed to be, “forward-looking statements.” These forward-looking statements can be identified by theuse of forward-looking terminology, including the terms “believes,” “estimates,” “anticipates,” “expects,” “intends,” “may,” “will” or “should” and include statementsargenx makes concerning the timing of its BLA submission to the FDA and the availability of efgartigimod to patients and physiciansand the therapeutic potential of its product candidates. By their nature, forward-looking statements involve risks and uncertaintiesand readers are cautioned that any such forward-looking statements are not guarantees of future performance. argenx’s actualresults 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, preclinicaland clinical trial and product development activities and regulatory approval requirements; argenx’s reliance on collaborationswith third parties; estimating the commercial potential of argenx’s product candidates; argenx’s ability to obtainand maintain protection of intellectual property for its technologies and drugs; argenx’s limited operating history; andargenx’s ability to obtain additional funding for operations and to complete the development and commercialization of itsproduct candidates. A further list and description of these risks, uncertainties and other risks can be found in argenx’sU.S. Securities and Exchange Commission (SEC) filings and reports, including in argenx’s most recent annual report on Form 20-Ffiled with the SEC as well as subsequent filings and reports filed by argenx with the SEC. Given these uncertainties, the readeris advised not to place any undue reliance on such forward-looking statements. These forward-looking statements speak only as ofthe date of publication of this document. argenx undertakes no obligation to publicly update or revise the information in thispress release, including any forward-looking statements, except as may be required by law.

For further information, please contact:

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

Exhibit 99.2

argenx Expands Capabilities In AntibodyEngineering Through Key Technology Partnerships

-     New partnerships with Chugai and the Clayton Foundation for Research provide access to innovative antibody engineering technologies

-     Extension of Halozyme collaboration supports long-term commitment to subcutaneous delivery options for patients

October 6, 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 the expansion of its technology capabilities in antibody engineering through new partnerships with Chugai and the Clayton Foundation. The Company is also broadening its collaboration with Halozyme to enable subcutaneous delivery for three additional current or future argenx products candidates. Through these partnerships, argenx gains access to innovative technologies to advance its differentiated pipeline and strengthen its position as a leader in immunology.

“Our Immunology Innovation Program, through which we partner with leading academic researchers, has been foundational in building our pipeline. In keeping with our commitment to expand and strengthen this program, we continue to make investments in our portfolio of antibody technologies. These new partnerships are a key part of the strategy to broaden our capabilities in antibody engineering in order to address new targets and develop first-in-class medicines for patients who need them,” commented Hans de Haard, Ph.D., Chief Scientific Officer of argenx. “Additionally, we announced the extension of our collaboration with Halozyme to secure our ability to offer subcutaneous delivery of current and future pipeline candidates. We are on a mission to improve the lives of people suffering from severe autoimmune diseases and cancer and believe that this long-term collaboration will allow us to reach the greatest number of patients.”

New Antibody Engineering Research Agreements

argenx has entered into two new research agreements to broaden its antibody engineering capabilities. Through these agreements, argenx can access world-class Fc engineering technologies to expand the therapeutic properties of future antibody candidates that emerge from its Immunology Innovation Program. The technologies will complement argenx’s current portfolio of Fc engineering technologies (NHANCE®, ABDEG™, POTELLIGENT®) and enable the Company to further differentiate and expand its pipeline of antibody candidates.

-	argenx and Chugai have entered into a research license and option agreement under which argenx<br>may access Chugai’s SMART-Ig® (“Recycling Antibody” and part of “Sweeping Antibody” technology)<br>and ACT-Ig® (Antibody half-life extending technology).
-	argenx and the Clayton Foundation have entered into a non-exclusive research agreement under which<br>argenx may access the Clayton Foundation’s proprietary DHS mutations to extend the serum half-life of therapeutic antibodies.
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Expansionof Access to Halozyme’s ENHANZE**® Technology**

argenx and Halozyme are expanding the existing global collaboration and license agreement that was signed in February 2019. Under the newly announced expansion, argenx gained the ability to access Halozyme’s ENHANZE® drug delivery technology for three additional exclusive targets upon nomination bringing the total to six potential targets under the collaboration. To date, two targets have been nominated including the human neonatal Fc receptor FcRn and complement component C2.

ENHANZE® has demonstrated across five FDA-approved products the ability to remove traditional limitations on the volume of biologics that can be delivered subcutaneously, potentially shortening drug administration time, reducing healthcare practitioner time, and offering additional flexibility and convenience for patients.

For more information about innovation at argenx, please visit the Company’s website at www.argenx.com/innovation.

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 in early and late stages of clinical development. 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/.

Forward-looking Statements

The contents of this announcement include statements thatare, or may be deemed to be, “forward-looking statements.” These forward-looking statements can be identified by theuse of forward-looking terminology, including the terms “believes,” “estimates,” “anticipates,” “expects,” “intends,” “may,” “will” or “should” and include statementsargenx makes concerning the intended benefits of its partnerships and the therapeutic potential of its product candidates. Bytheir nature, forward-looking statements involve risks and uncertainties and readers are cautioned that any such forward-lookingstatements are not guarantees of future performance. argenx’s actual results may differ materially from those predicted bythe forward-looking statements as a result of various important factors, including argenx’s expectations regarding its theinherent uncertainties associated with competitive developments, preclinical and clinical trial and product development activitiesand regulatory approval requirements; argenx’s reliance on collaborations with third parties; estimating the commercial potentialof argenx’s product candidates; argenx’s ability to obtain and maintain protection of intellectual property for itstechnologies and drugs; argenx’s limited operating history; and argenx’s ability to obtain additional funding for operationsand 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 reportsfiled by argenx with the SEC. Given these uncertainties, the reader is advised not to place any undue reliance on such forward-lookingstatements. These forward-looking statements speak only as of the date of publication of this document. argenx undertakes no obligationto publicly update or revise the information in this press release, including any forward-looking statements, except as may berequired by law.

For further information, please contact:

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