Cold agglutinin disease (CAD) is a rare type of autoimmune hemolytic anemia, caused by cold-reacting autoantibodies. Hemolysis is complement-dependent, classical pathway-mediated, resulting in erythrocyte opsonization with predominant extravascular destruction and ensuing anemia. Alexander Röth, MD, West German Cancer Center, University Hospital Essen, University of Duisburg-Essen, Essen, Germany, presents the results from the phase 3 Cardinal study (NCT03347396). The purpose of this trial was to assess efficacy and safety of sutimlimab, a first-in-class selective inhibitor of the complement pathway, in adults with CAD who have a recent history of transfusion. Results demonstrated that sutimlimab has a rapid and sustained treatment effect in CAD, indicating that it has the potential to change treatment practices for patients with this condition. This press briefing was recorded at the American Society of Hematology (ASH) 2019 Annual Meeting and Exposition in Orlando, FL.