Humate P Is For Patients with Von Willebrand Disease (vWD)
Von Willebrand disease, or vWD, is an inherited disorder that impacts the blood's ability to clot properly. It takes its name from Dr. Erik von Willebrand, who first described the condition in 1926. As a group, bleeding disorders (including hemophilia) are rare. Von Willebrand disease is the most common inherited bleeding disorder, affecting as much as 1% of the population or more.It is the most common inherited bleeding disorder in humans, and several other serious bleeding and clotting diseases, including thrombotic thrombocytopenic purpura.
Hereditary coagulation factor deficiencies (HCFD) have been reported from all parts of the world. Haemophilia and von Willebrand disease (vWD) are the most common types of hereditary factor deficiencies. Other types are much rarer . The incidence of haemophilia does not seem to vary between different geographic areas or ethnic groups ; vWD, on the other hand, does . The severity of the resulting bleeding tendency and the pattern of bleeding varies between the different types of factor deficiency. Some may only cause a mild bleeding tendency, while others can cause lifelong severe bleeding problems.
Treatment of von Willebrand disease focuses on stopping or preventing bleeding episodes, typically by using medications that increase the levels and activity of von Willebrand clotting factor and related substances in your blood. Von Willebrand disease affects males and females in approximately equal proportions and is present in up to 1 percent of the U.S. population.
Von Willebrand disease (vWD) is the most common hereditary coagulation abnormality described in humans, although it can also be acquired as a result of other medical conditions. It arises from a qualitative or quantitative deficiency of von Willebrand factor (vWF), a multimeric protein that is required for platelet adhesion. It is known to affect humans and in veterinary medicine, dogs.
A substance in the blood known as von Willebrand factor helps platelets stick to damaged blood vessels. Another function of von Willebrand factor is to carry the important clotting protein, called factor VIII, in the blood. People with von Willebrand disease have a problem with one or both of these blood components.
Von Willebrand disease is caused by a deficiency of von Willebrand factor. Von Willebrand factor helps platelets to clump together and stick to the blood vessel wall, which is necessary for normal blood clotting. Thrombotic thrombocytopenic purpura is a potentially fatal disease characterized by widespread platelet thrombi in the microcirculation. In the normal circulation, von Willebrand factor is cleaved by a plasma protease.
Inhibitory antibodies against von Willebrand factor–cleaving protease occur in patients with acute thrombotic thrombocytopenic purpura. A deficiency of this protease is likely to have a critical role in the pathogenesis of platelet thrombosis in this disease.Medications such as desamino-8-arginine vasopressin (DDAVP) can be given to raise the levels of von Willebrand factor, which will reduce the tendency toward bleeding.
In February 2007, the U.S. Food and Drug Administration (FDA) approved Alphanate to decrease bleeding in patients with the disease who must have surgery or other invasive procedure.
Blood plasma or certain factor VIII preparations may also be used to decrease bleeding.A link between thrombotic thrombocytopenic purpura and abnormal immune reactions has been suggested.Treatment with glucocorticoids or immunoadsorption with staphylococcal protein A may induce a remission of the disease, but even in the absence of immunosuppression thrombotic thrombocytopenic purpura does not recur in most patients who are successfully treated with plasmapheresis. The transient nature of acute thrombotic thrombocytopenic purpura raises the possibility that the antibodies to the protease represent a deranged response to certain triggering events.
Some types of von Willebrand disease do not respond to DDAVP. Tests should be done to determine a patient's specific type of von Willebrand disease, before trauma or surgery occurs. A trial of DDAVP can be done prior to surgery to test whether von Willebrand factor levels increase.
The U.S. Food and Drug Administration (FDA) today approved Humate-P (Antihemophilic Factor/von Willebrand Factor Complex) for the prevention of excessive bleeding during and after surgery in certain patients with mild to moderate and severe von Willebrand disease (vWD). The disease is the most common inherited bleeding disorder, affecting about 1 percent of the U.S. population.
Humate-P is the second biological product to be approved for the management of surgery and invasive procedures in patients with vWD in whom the medication desmopressin may not work. The first biological product, Alphanate, was approved by FDA in February. However, Humate-P is the first product specifically for patients with severe vWD who are undergoing major surgery.
"This is an important advance for patients with vWD, including those who are severely affected by the disorder," said Jesse Goodman, M.D., M.P.H., director of FDA's Center for Biologics Evaluation and Research. “Humate-P provides a preventive therapy that can make needed surgery not only possible, but also safer."
The product was originally approved for use in adult patients to treat and prevent bleeding from hemophilia A. It was later approved to treat spontaneous and traumatic bleeding for severe vWD and for mild and moderate vWD when desmopressin use is known or suspected to be inadequate.
Humate-P is made by purification of the needed clotting protein from human plasma from carefully screened and tested U.S. donors. It undergoes steps to further reduce the risk for transfusion-transmitted diseases. While the risk for the transmission of bloodborne diseases is very low, it can not be eliminated.
FDA based its approval on a clinical study of Humate-P in 35 patients suffering from vWD who underwent a total of 28 major and seven minor surgical procedures. The product was judged excellent or good in 91 percent of the patients who avoided severe hemorrhage. The most common adverse reaction following surgery was hemorrhage, in 30 percent of the patients; however, only 9 percent of the hemorrhages were classified as severe. Other adverse reactions in patients following surgery included nausea (24 percent) and pain (17 percent).
Men and women are equally affected by vWD, which is caused by a deficiency or defect in certain plasma proteins critical to blood clotting. In most cases, the disease is mild, and treatment usually is not required to stop bleeding. However, about 2,000 people in the United States each year suffer from moderate and severe forms of the disease in which bleeding can be excessive if not treated and possibly cause delayed wound healing.