What potential interaction can occur when emicizumab is combined with recombinant activated factor VII (rFVIIa) or factor VIII?

Combining emicizumab with rFVIIa or factor VIII may cause hypercoagulability based on preclinical experiments, and because emicizumab increases coagulation potential, lower rFVIIa or factor VIII doses may achieve haemostasis than without Hemlibra prophylaxis; no adequate or well-controlled interaction studies have been conducted.