Change to the Board of Directors

July 15, 2015

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 that non-executive director Michael B. Sheffery, representing Orbimed Advisors, will resign from the Board of Directors per 26 August 2015.

Mr. Michael B. Sheffery has been involved with arGEN-X B.V. since the venture capital investment of Orbimed Advisors in 2011. The resignation of Mr. Michael B. Sheffery is in line with the company's aim to gradually replace all of its originally investor appointed non-executive directors with independent industry professionals, in accordance with the requirements of the Dutch Corporate Governance Code.

“We would like to take this opportunity to thank Michael for his very important contributions as Director over the past years. We greatly appreciate all he has done to help us develop arGEN-X,” commented Peter Verhaeghe, Chairman of the Board of Directors.