Mechanism of Action

Leverage the hemostatic potential of HMW multimers

The size of von Willebrand factor (VWF) multimers directly correlates with their in vitro function.^{1, 2}

High molecular weight (HMW) VWF multimers are most essential for primary hemostasis, whereas low molecular weight (LMW) multimers are less functionally active²
HMW-VWF multimers have been shown to be associated with increased hemostatic activity³
HMW-VWF multimers are associated with shortened bleeding time³

The process of blood coagulation has two distinct stages of hemostasis: primary hemostasis and secondary hemostasis. While factor VIII (FVIII) has a role in secondary hemostasis, von Willebrand factor (VWF) protein is a key component in primary hemostasis.

People with VWD have an insufficient amount of VWF protein in the blood, or VWF that is defective. Because VWF is essential in primary hemostasis, an insufficient amount or a supply of defective VWF interferes with proper platelet adherence or aggregation. The mainstay of VWD treatment is the replacement of the deficient VWF protein. This results in shortened bleeding time and correction of the coagulation abnormality.

The VWF profile of Humate-P strongly correlates to hemostatic activities during the stages of hemostasis^2,4

Slides 1, 2, and 3 illustrate the crucial role of VWF in primary hemostasis, while Slide 4 shows the process of secondary hemostasis. Slide 5 illustrates how LMW-VWF multimers form a sub-optimal hemostatic plug.

Successful completion of both stages of hemostasis results in the final step of the clotting process, the formation of a stable hemostatic plug.

Multimeric patterns similar to normal human plasma (NHP)

Like NHP, Humate-P contains a high percentage of HMW-VWF multimers, and can correct the hemostatic defect in patients with VWD.^1,3

View an animated densitometric analysis comparing various VWF/FVIII concentrates and normal human plasma.

Important Safety Information

Humate-P is indicated for treatment and prevention of bleeding in adult patients with hemophilia A (classical hemophilia). Humate-P is also indicated in adult and pediatric patients with von Willebrand disease (VWD) for (1) treatment of spontaneous and trauma-induced bleeding episodes, and (2) prevention of excessive bleeding during and after surgery. This applies to patients with severe VWD, and patients with mild and moderate VWD for whom use of desmopressin is known or suspected to be inadequate. Humate-P is not indicated for the prophylaxis of spontaneous bleeding episodes.

Humate-P is contraindicated in individuals with a history of anaphylactic or severe systemic response to antihemophilic factor or von Willebrand factor preparations.

Monitor for intravascular hemolysis and decreasing hematocrit values in patients with A, B, and AB blood groups who are receiving large or frequent doses. Also monitor VWF:RCo and FVIII levels in VWD patients, especially those undergoing surgery.

Thromboembolic events have been reported in VWD patients receiving coagulation factor replacement. Caution should be exercised and antithrombotic measures considered, particularly in patients with known risk factors for thrombosis.

Humate-P is derived from human plasma. The risk of transmission of infectious agents, including viruses and, theoretically, the Creutzfeldt-Jakob disease (CJD) agent, cannot be completely eliminated.

In patients receiving Humate-P in clinical studies for treatment of VWD, the most commonly reported adverse reactions observed by >5% of subjects are allergic-anaphylactic reactions, including urticaria (hives), chest tightness, rash, pruritus (itching), and edema (swelling). For patients undergoing surgery, the most common adverse reactions are postoperative wound or injection-site bleeding, and epistaxis (nosebleed).

Please see full prescribing information.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch or call 1-800-FDA-1088.

References