arGEN-X Completes First Dosing of ARGX-113 for Severe Autoimmune Disorders

• Potential breakthrough therapy for treatment of autoimmune crisis
• Fourth arGEN-X drug candidate entering human trials in 6 years of operations

Breda, the Netherlands / Ghent, Belgium– arGEN-X N.V. (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 announces the completion of the first human dosing of ARGX-113, a potential breakthrough therapy for the treatment of autoimmune crisis.

The first dosing of healthy volunteers in our Phase 1 study marks an important step forward for ARGX-113. ARGX-113 has a completely novel approach to managing acute crises related to a large number of IgG-mediated autoimmune diseases such as systemic lupus erythematosus as well as a wide range of serious autoimmune orphan diseases for which there are currently insufficient treatment options, comments Tim Van Hauwermeiren, CEO of arGEN-X. ARGX-113 demonstrated high potency and rapid onset of action in a preclinical setting and has an exciting potential to treat patients in high unmet medical need.

The Phase 1 study is a double-blinded and placebo-controlled study in healthy volunteers. The objective is to evaluate the safety and tolerability profile of ARGX-113 and to identify a potential dose for future Phase 2/3 studies. Topline results from the Phase 1 study are expected in the first half of 2016.