Breda, the Netherlands / Ghent, Belgium– arGEN-X N.V. (arGEN-X, 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, announces today the partial exercise of the over-allotment option by KBC Securities (the Stabilization Manager) acting on behalf of KBC Securities and Kempen & Co (the Joint Global Coordinators) and Petercam (the Co-Lead-Manager); and the end of the stabilization period, in relation to its Initial Public Offering that ended on 8 July 2014 (the IPO).