argenx to provide updates on ARGX-113 and ARGX-110 during American Society of Hematology Annual Meeting

Workshop to occur on Sunday December 4th at 11:00 am PT

Breda, the Netherlands / Ghent, Belgium – argenx (Euronext Brussels: ARGX), a clinical-stage biopharmaceutical company focused on creating and developing differentiated therapeutic antibodies for the treatment of cancer and severe autoimmune diseases, today announced that it will provide updates on its two lead programs, ARGX-113 and ARGX-110, during a workshop being held today in conjunction with the American Society of Hematology (ASH) Annual Meeting.

The workshop is being held on Sunday December 4th at 11:00 am PT. The presentation of the event will be available on the Company’s website at

ARGX-113: New clinical data will be presented from the multiple ascending dose Phase I study in healthy volunteers showing comparable pharmacodynamics and pharmacokinetic patterns between the lower dose (10 mg/kg) and higher dose (25 mg/kg), justifying the selection of the lower dosing regimen for upcoming Phase II clinical trials. In addition, preclinical proof of concept data supporting myasthenia gravis (MG) and immune thrombocytopenia (ITP) as lead indications for Phase II clinical trials will be presented. argenx anticipates to start the first Phase II study in MG before the end of the year and in ITP in the first quarter of 2017.

ARGX-110: Further efficacy and safety data will be presented from the currently ongoing Phase Ib study in relapsed/refractory T-cell lymphoma (TCL) patients who failed multiple lines of therapy: 5 out of 10 patients show encouraging signs of clinical activity including partial response (3/10) and stable disease (2/10). ARGX-110 continues to show a favorable safety and tolerability profile. Additionally, preclinical data supporting the start of the first combination study in newly diagnosed, elderly acute myelogenous leukemia (AML) patients will be reported. The preclinical work on ARGX-110 in AML was done in collaboration with the Tumor Immunology Lab of Prof. A. F. Ochsenbein at the University of Bern, who won the prestigious 2016 Otto Naegeli Prize for his breakthrough research on CD70/CD27 signaling with therapeutic potential for cancer patients.

About ARGX-113

ARGX-113 is a potential breakthrough therapy for treatment of IgG-mediated autoimmune diseases. ARGX-113 is the Fc-portion of an antibody that has been modified by the argenx proprietary ABDEG™ technology to increase its affinity for FcRn beyond that of normal IgG antibodies. As a result, ARGX-113 blocks antibody recycling and leads to fast depletion of the autoimmune disease-causing IgG autoantibodies. The development work on ARGX-113 is done in close collaboration with the Department of Immunology of Prof. E. Sally Ward at the University of Texas Southwestern Medical.

About ARGX-110

ARGX-110 is a SIMPLE Antibody™ targeting CD70, an immune checkpoint target involved in hematological malignancies, several solid tumors and severe autoimmune diseases. ARGX-110 works in three ways: i) blocks growth of tumor cells, ii) kills cancer cells and iii) restores immune surveillance against tumors(Silence K. et al. mAbs 2014; 6 (2):523-532). ARGX-110 is currently being evaluated in hematological and solid tumors.

About argenx

argenx combines the diversity of the llama immune system with antibody engineering to advance a clinical pipeline to treat patients with cancer and autoimmune diseases. Our platforms allow us to unlock novel and complex targets and develop antibody-based drugs designed for longer duration of effect and greater efficacy. The strength of our team, our deep understanding of the biology, and our committed collaborations with industry leaders contribute to the success of our journey.

For further information, please contact:

Joke Comijn, Corporate Communications Manager

+32 (0)477 77 29 44

+32 (0)9 310 34 19

[email protected]

Beth DelGiacco (US IR)

Stern Investor Relations

+1 212 362 1200

[email protected]

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’s 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.