arGEN-X Enters Long-term Strategic Alliance with Shire Pharmaceuticals in Therapeutic Antibodies

• Significantly expanded relationship created on back of collaboration success

Breda, the Netherlands / Ghent, Belgium– arGEN-X, a clinical-stage biopharmaceutical company focused on creating and developing differentiated therapeutic antibodies for the treatment of cancer and severe autoimmune diseases, today announced it has entered into a long-term strategic alliance with Shire Pharmaceuticals. Under the agreement, arGEN-X will bring its entire suite of human antibody discovery technologies to a partnership focused on multiple targets aligned with Shire’s therapeutic focus. The multi-year initiative aimed at helping augment the Shire development pipeline follows an initial research and development collaboration undertaken in March 2012.

Our partnering philosophy at arGEN-X is to create alliances for the long term with select, top tier companies. We have certainly upheld this principle by repeatedly expanding our collaboration with Shire, with today’s announcement marking our most ambitious and exciting venture with them to date, said Tim Van Hauwermeiren, CEO of arGEN-X. We have enjoyed consistent success in our collaboration, recognizing important synergies in combining our strengths and capabilities. While we continue to see Shire as our development partner in this new alliance, we value this opportunity to bring programs into our own pipeline to further our ambitions as a clinical stage, product-focused company.

Shire will make a total upfront investment of €15 million (US$20.4 million) in arGEN-X, consisting of €3 million in cash and €12 million in equity. In addition, it will fund the collaborative research programs at arGEN-X and pay fees, clinical, regulatory and sales milestones, as well as single digit royalties on therapeutic product sales. Shire will be responsible for clinical development and commercialization of products, with arGEN-X having the right to license any programs not pursued by Shire into its own development pipeline.

Dr. Philip J. Vickers, Global Head of Research and Development at Shire commented: Our arGEN-X collaboration has exceeded our expectations in delivering highly differentiated antibody programs within our therapeutic focus. The time is right to commit more significantly to the company through a longer term investment in its unique, world class technologies.