Emicizumab for the Prevention of Bleeding in Patients with Hemophilia A

Most individuals with severe hemophilia A infuse factor VIII concentrates two or three times per week to prevent hemorrhages. Emicizumab, a subcutaneously injectable monoclonal antibody that can substitute for intravenously infusible factor VIII in the clotting process, was approved in 2017 for the treatment of patients with hemophilia A and inhibitors (NEJM JW Oncol Hematol Sept 2017 and N Engl J Med 2017; 377:809).

To assess whether emicizumab could replace factor VIII prophylaxis in hemophilia patients without inhibitors, investigators conducted two industry-sponsored studies involving a total of 152 patients who were 12 years of age or older. In the first trial, 89 patients not currently receiving factor VIII prophylaxis were randomized …