Intensive care medicine

Coagulation

Thrombin generation

Thrombin

Internal medicine

Pharmacology

Medicine

Platelet

Haematologica

Emicizumab is a recombinant, humanized, bispecific, monoclonal antibody that bridges activated factor IX and factor X to restore the function of deficient factor VIII. Treatment of bleeding in patients with hemophilia and inhibitors involves the use of bypassing agents (BPA).These molecules are also used for the management of breakthrough bleeds in patients on prophylaxis with emicizumab, with increased concerns about the risks of combining two procoagulant drugs. Using thrombin generation assay, we tailored the dosage of activated prothrombin complex concentrate (APCC) and successfully treated an acute spontaneous arterial bleeding in a patient on prophylaxis with emicizumab 1.5mg.kg-1. Low dosages of APCC 15-25U.kg-1 were sufficient to normalize thrombin generation. The patient safely recovered with no thrombotic complications despite multiple infusions of APCC given during a 3-week period. We also showed that recombinant factor IX concentrates might represent an alternative to BPA in treating breakthrough bleeds in patients receiving prophylaxis with emicizumab.

Use of thrombin generation assay to personalize treatment of breakthrough bleeds in a patient with hemophilia and inhibitors receiving prophylaxis with emicizumab