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, has completed enrolment of a first cohort of 15 patients with CD70-positive solid tumors into an open-label Phase 1b expansion trial with ARGX-110, a novel anti-CD70 therapeutic antibody.