argenx to host conference call & webcast to report fourth quarter business update and full year 2016 financial results on March 15, 2017

Breda, the Netherlands / Ghent, Belgium – argenx (Euronext Brussels: ARGX), a clinical-stage biotechnology company developing a deep pipeline of differentiated antibody-based therapies for the treatment of severe autoimmune diseases and cancer, today announced it will host a conference call and audio webcast on Wednesday, March 15, 2017 at 3:00 pm CET (10:00 am EDT) to discuss the 2016 financial results, as well as provide a fourth quarter business update.

To participate in the conference call, please select your phone number below, and use the confirmation code 75576807. The webcast may be accessed on the homepage of the argenx website at www.argenx.com or by clicking here.

A replay of the webcast will also be available on the argenx website.

About argenx

argenx a clinical-stage biotechnology company with a deep pipeline of differentiated antibody-based therapies intended for the treatment of severe auto-immune diseases and cancer. We are focused on developing product candidates that are either first-in-class against novel targets or best-in-class against known, but complex, targets to treat diseases with a significant unmet medical need. Our ability to execute on this focus is enabled by our suite of differentiated technologies. Our SIMPLE AntibodyTM Platform, based on the powerful llama immune system, allows us to exploit novel and complex targets, and our three antibody engineering technologies enable us to expand the therapeutic index of our product candidates.

www.argenx.com

Dial-In Numbers:

Participant Free Call Dial-In Numbers:

UK 0800 694 0257

Participant Standard International Dial-In:

UK Standard International +44 (0) 1452 555 566

Participant UK Local Call Dial-In Numbers:

UK 0844 493 3800

UK National Call 0871 700 0345

Participant Local Call Dial-In Numbers:

Australia 0290 371 687

Austria 0192 865 68

Belgium 0817 000 61

Croatia 0177 766 11

Czech Republic 2288 804 60

Denmark 3272 7625

Finland 0923 195 187

France 0176 742 428

Germany 0692 222 3479

Germany 0692 222 4918

Hungary 0618 088 303

India 0223 098 5304

Ireland 0143 196 48

Ireland 0150 601 53

Italy 0236 008 146

Latvia 6778 2516

Luxembourg 2088 0695

Netherlands 0207 176 886

New Zealand 0992 917 07

Norway 2156 3013

Poland 2230 701 18

Romania 0318 144 957

Russia 4996 771 036

Slovenia 0160 093 64

South Africa 2110 032 02

Spain 9141 436 69

Sweden 0850 336 434

Switzerland 0565 800 007

USA 1631 510 7498

For further information, please contact:

Joke Comijn, Corporate Communications Manager

+32 (0)477 77 29 44

+32 (0)9 243 40 70

info@argenx.com

Beth DelGiacco (US IR)

Stern Investor Relations

+1 212 362 1200

beth@sternir.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 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’ actual results may differ materially from those predicted by the forward-looking statements. argenx undertakes no obligation to publicly update or revise forward-looking statements, except as may be required by law. Management’s Discussion and Analysis of Financial Condition and Results of Operations