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, announced today the submission of an Investigational New Drug (IND) application to the U.S. Food and Drug Administration (FDA) to initiate a Phase 1b/2 trial of ARGX-110 in patients with relapsed or refractory Waldenström’s macroglobulinemia.