[Advances in the therapy for von Willebrand disease]

Von Willebrand disease (VWD) is caused by quantitative or qualitative deficiencies in the von Willebrand factor (VWF). VWF concentrate replacement therapy is required in certain situations, such as severe VWD subtype or critical bleeding, even in mild VWD subtypes. A single plasma-derived factor VIII/VWF concentrate has been available for decades in Japan. However, it has a theoretical risk of infectious disease transmission, allergic reactions, and thrombosis. A recombinant VWF (vonicog alfa) was approved by the Japanese Pharmaceuticals and Medical Devices Agency in 2020. Vonicog alfa is the only VWF product that contains ultralarge multimer, suggesting both effective bleeding control and excessive platelet plug formation. The efficacy and safety of vonicog alfa have been confirmed by three phases of clinical studies for on-demand usage, elective surgery, and prophylaxis. We also have a successful experience with vonicog alfa with minimal adverse events in two cases (hemostatic treatment in a patient with recurrent epistaxis and prophylaxis for delivery in a pregnant woman).