Von Willebrand Factor/Coagulation Factor Viii Complex (Human)

Introduction Overview

Generic Name

von Willebrand Factor/Coagulation Factor VIII Complex (Human)

Brand Name

Wilate

Dosage Form

Injection for infusion

Drug Class

Miscellaneous coagulation modifiers

Pharmacokinetics

Absorption:
Wilate is administered intravenously, which allows direct entry of the von Willebrand Factor (VWF) and Coagulation Factor VIII (FVIII) complex into the bloodstream, bypassing any absorption barriers that occur with other routes such as oral or intramuscular administration. Because of its intravenous administration, Wilate has 100% bioavailability, with rapid onset of action as the factors are immediately available in the circulatory system. The absorption phase is thus effectively instantaneous and does not pose clinically significant pharmacokinetic variability.

Distribution:
Following intravenous administration, the VWF/FVIII complex distributes primarily within the intravascular space due to its large molecular size and plasma protein nature. The distribution volume approximates plasma volume, reflecting confinement within the vascular compartment. VWF acts as a carrier protein for FVIII, stabilizing it and prolonging its half-life by preventing premature degradation. The binding of FVIII to VWF in the circulation provides a reservoir of active coagulation factor available for rapid mobilization upon vascular injury.

Metabolism:
Both VWF and FVIII are large glycoproteins metabolized primarily by the reticuloendothelial system through proteolytic degradation in endothelial cells, hepatocytes, and macrophages. FVIII metabolism is modulated by its association with VWF, which protects FVIII from early clearance. Variations in metabolic degradation rates may occur in different patient populations, such as those with liver dysfunction, but Wilate’s protein components follow established catabolic pathways for coagulation factors. Viral inactivation steps in manufacturing do not affect pharmacokinetics but are critical for safety.

Elimination:
Elimination of VWF and FVIII occurs via reticuloendothelial cells and is characterized by a half-life dependent on several factors, including the patient's endogenous VWF levels, clearance mechanisms, and presence of inhibitors (antibodies). The half-life of FVIII when administered alongside VWF in Wilate is typically approximately 12 hours but can vary. Clearance is affected by immune responses, particularly the development of neutralizing antibodies which can result in rapid clearance and reduced clinical efficacy. No significant renal or hepatic elimination is observed, consistent with plasma protein characteristics. Monitoring plasma levels during therapy guides dosing intervals to maintain hemostasis.

Dosage Forms

Available Dosage Forms:
Wilate is available as a powder for injection which requires reconstitution prior to intravenous infusion.

Specific marketed vial strengths include:
- Single-Dose Vial: 500 International Units (IU)
- Single-Dose Vial: 1000 International Units (IU)

The powder must be mixed aseptically with the provided diluent to prepare the solution for infusion. After reconstitution, the solution should be used within 4 hours and stored at room temperature; refrigeration is not recommended post reconstitution.

Dosages for Adults and Adolescents:
The dosing of Wilate varies based on indication (on-demand treatment, perioperative management, or routine prophylaxis), severity of bleeding, and individual patient factors including body weight and clinical response. Typically, dosing is calculated in International Units per kilogram (IU/kg) of body weight, with infusion rates recommended at 2-4 mL per minute.

Routine prophylaxis involves repeated infusions administered to maintain factor levels sufficient to prevent spontaneous bleeding, often tailored by pharmacokinetic monitoring.

Specific Patient Populations:
For pediatric patients aged 6 years and older with von Willebrand Disease or Hemophilia A, dosing regimens are adjusted accordingly. Individualized dosing guided by factor activity levels is essential in patients with inhibitors, renal or hepatic impairment, or those at risk for thromboembolic events.

Patients with life-threatening bleeding or undergoing major surgery may require higher doses and more frequent monitoring and dosing adjustments.

Mechanism Of Action

Wilate acts by supplying exogenous von Willebrand factor (VWF) and coagulation Factor VIII (FVIII) to patients with deficiencies in these proteins. VWF is essential for primary hemostasis as it mediates platelet adhesion to subendothelial surfaces at sites of vascular injury, facilitating platelet aggregation and plug formation. Additionally, VWF serves as a stabilizing carrier protein for FVIII, preventing its rapid proteolytic degradation in plasma and maintaining a proper circulating half-life.

Upon intravenous administration, Wilate temporarily restores deficient or dysfunctional VWF and FVIII in patients suffering from von Willebrand Disease (VWD) or Hemophilia A. The administered FVIII binds to the VWF in circulation, creating a complex that is critical for the intrinsic coagulation pathway. Activated FVIII (FVIIIa) acts as a cofactor to activated Factor IX (FIXa), enhancing the activation of Factor X to Factor Xa, a crucial enzymatic step that leads to thrombin generation and ultimately stabilizes fibrin clot formation.

Compared to other treatments such as recombinant FVIII products or desmopressin (DDAVP), Wilate provides both VWF and FVIII thereby addressing the dual deficiency typical in VWD and offering a comprehensive replacement solution. This dual factor replacement is especially important in type 3 VWD patients who have very low or absent VWF. Clinical studies have demonstrated that Wilate effectively elevates plasma levels of VWF activity and FVIII coagulant activity, reducing bleeding episodes and controlling hemorrhages during surgical procedures.

Research confirms that Wilate’s viral inactivation and purification steps do not compromise the functional integrity of VWF and FVIII, thus maintaining the hemostatic efficacy essential in clinical use. Its mechanism ensures restoration of both platelet function and coagulation cascade activity, critical for effective hemostasis in bleeding disorders.

Pharmacological Actions

Replacement therapy supplying von Willebrand Factor (VWF) and coagulation Factor VIII (FVIII).
Promotion of platelet adhesion to damaged endothelium via VWF.
Stabilization and prolongation of circulating FVIII half-life through VWF binding.
Enhancement of the intrinsic coagulation pathway resulting in thrombin and fibrin clot formation.
Correction of bleeding tendency by temporarily restoring deficient coagulation factors.
Reduction of spontaneous and trauma-induced bleeding episodes in VWD and Hemophilia A.
Supports perioperative hemostasis management during surgeries.
Provides prophylactic treatment to reduce the frequency of bleeding episodes.
Acts quickly due to intravenous administration for on-demand bleeding control.
Bypasses endogenous synthesis defects or deficiencies in patients with hereditary factor deficiencies.
Does not possess anticoagulant or platelet inhibitory effects.
Does not affect other coagulation factors directly but acts via FVIII and VWF.
Prevents premature degradation of FVIII, enhancing its duration of effect.
Includes pathogen inactivation steps to reduce infectious agent transmission risk.
Compatible with standard intravenous infusion techniques.

Therapeutic Or Clinical Uses

Treatment of bleeding episodes in patients with von Willebrand Disease (all types).
On-demand control of acute hemorrhage events associated with VWD.
Perioperative management to prevent or minimize surgical bleeding in patients with VWD and Hemophilia A.
Routine prophylaxis in patients aged 6 years and older with VWD to reduce bleeding frequency.
Treatment and prophylaxis of bleeding episodes in adults and adolescents with Hemophilia A.
Management of bleeding tendencies associated with severe Factor VIII deficiency.
Used in patients who are unresponsive to or unsuitable for desmopressin (DDAVP) therapy.
Therapy for controlling bleeding in trauma or injury in hereditary coagulation factor deficiencies.
Supportive treatment in dental procedures or minor surgical interventions.
Adjunct for patients with inhibitors to FVIII where specific immunomodulatory treatment is involved.
Reduction of spontaneous joint and muscle bleeds in prophylactic regimens.
Treatment of mucocutaneous bleeding manifestations.
Use in cases of gastrointestinal bleeding related to VWD.
Management of excessive bleeding during childbirth in affected women.
Therapeutic replacement in hereditary coagulation disorders to prevent life-threatening hemorrhage.

Side Or Adverse Effects

Hypersensitivity reactions including anaphylaxis, with signs such as hives, wheezing, chest tightness, and hypotension.
Urticaria (hives) and rash.
Dizziness and headache.
Fever, especially observed in hemophilia A patients.
Local reactions at injection site including redness, pain, or swelling.
Nosebleeds (epistaxis).
Numbness or tingling sensations possibly related to vascular or neurological events.
Back pain reported in some cases post infusion.
Potential development of neutralizing antibodies (inhibitors) against VWF or FVIII leading to decreased efficacy.
Thromboembolic events including blood clots; higher risk with multiple infusions.
Bleeding at wound or injection sites if adequate factor levels are not achieved.
Rare transmission of infectious agents despite viral inactivation steps in manufacturing.
Allergic reactions despite precautions, including facial swelling or difficulty breathing.
Sweating or hot flashes occurring during or after infusion.
Fatigue or weakness associated with the primary disease or infusion reactions.

Precautions

Do not use in patients with a history of severe allergic reactions to antihemophilic factor products or human plasma-derived components.
Use caution in patients with known hypersensitivity to any product ingredients or components of packaging.
Monitor closely for hypersensitivity reactions during and after infusion; discontinue immediately if severe.
Patients should inform healthcare providers of any prior thromboembolic events or predisposition to thrombosis.
Observe for signs of inhibitor development, especially in type 3 von Willebrand Disease patients.
Frequent blood testing to monitor factor levels and clinical response is essential during treatment.
Pregnant or breastfeeding women should use under medical supervision, evaluating risk versus benefit.
Vaccination for hepatitis may be recommended prior to starting therapy due to plasma-derived origin.
Follow aseptic techniques during preparation and administration to avoid infection.
Avoid use beyond expiration date or if product shows discoloration or particulate matter after reconstitution.
Storage instructions must be strictly followed to preserve drug stability and efficacy.
Patients should be educated on proper home infusion techniques and disposal of medical waste.
Medical alert identification is advised for patients with bleeding disorders treated with Wilate.
Dose adjustments may be required based on renal or hepatic function although no direct elimination via these organs.
Caution when administered concomitantly with other agents affecting coagulation.

Warnings

Risk of hypersensitivity reactions, including anaphylaxis, necessitating immediate cessation of infusion and emergency care.
Potential thromboembolic events with repeated high doses or prolonged treatment require vigilant monitoring.
Development of neutralizing antibodies to VWF can result in inadequate hemostatic response and treatment failure.
Transmission of infectious agents is a theoretical risk despite rigorous viral inactivation and donor screening.
Do not use in patients with known allergies to human plasma products or any component of Wilate formulation.
Careful consideration for use in patients with history of stroke or thrombotic disorders due to clotting risk.
Proper reconstitution and timely use after preparation (within 4 hours) is critical to avoid loss of potency or contamination.
Avoid freezing the product and do not return to refrigerated storage once stored at room temperature.
Discontinue use immediately if severe hypersensitivity symptoms develop including generalized urticaria, chest tightness, or hypotension.
Administration should be supervised by healthcare professionals experienced in coagulation disorders.
Regular assessment of clinical efficacy and factor activity levels is necessary to guide therapy and dosing.
Patients with type 3 VWD are at higher risk of inhibitor development and may require specialized management.
Caution in patients undergoing multiple treatments with Wilate as risk of thrombotic complications increases.
Emergency medical information should be readily available when administering Wilate.
Use with caution in elderly patients who may have an increased thromboembolic risk.

Contraindication

Known hypersensitivity to Wilate, its ingredients, or any human plasma-derived coagulation factor products.
History of severe allergic or anaphylactic reaction to antihemophilic factors.
Patients with previous hypersensitivity to components used in drug formulation or container.
Contraindicated in patients with thrombosis or known active thromboembolic events without appropriate medical supervision.
Should not be used if the product vial content shows discoloration, particulate matter, or other signs of contamination.
Use is contraindicated if storage conditions have been breached, such as freezing or exceeding expiration date.
Known allergy to polysorbate 80 or other excipients present in the product formulation.
Patients with known inhibitors to Factor VIII may have reduced response; hence use should be guided strictly by specialist supervision.
Not indicated for use in diseases other than von Willebrand Disease and Hemophilia A without specific physician recommendation.
Patients with IgA deficiency with antibodies to IgA may have increased risk of hypersensitivity reactions and should be treated cautiously.

Drug Interactions

Concomitant use with anticoagulants (e.g., warfarin, heparin) may modify bleeding risk and requires monitoring.
Potential interaction with antiplatelet agents (e.g., aspirin, clopidogrel) can affect hemostasis efficacy.
Interaction with other hemostatic agents including desmopressin (DDAVP) may necessitate dose adjustments.
Avoid concurrent use with agents that may increase thrombotic risk without careful clinical supervision.
Co-administration with medications affecting liver metabolism may alter coagulation factor activity indirectly.
No known significant pharmacokinetic interactions due to plasma-derived protein nature, but monitoring is advised.
Simultaneous administration with blood products may alter laboratory coagulation testing results.
Use caution when combined with procoagulant or fibrinolytic agents to avoid bleeding or clotting complications.
No documented interactions with common over-the-counter vitamins or herbal supplements, but disclosure to healthcare providers is recommended.
Inhibitory antibody development can be affected by concomitant immunosuppressive therapies, impacting drug effectiveness.
Drugs causing platelet dysfunction may diminish the clinical benefits of Wilate.
Careful coordination with vaccination schedules recommended when initiating Wilate therapy.
Monitoring required if administered alongside drugs that prolong bleeding time or affect coagulation cascade.
Potential interaction with agents causing hypersensitivity reactions; close observation warranted.
No reported drug-food interactions; standard dietary recommendations apply during treatment.

Preparations Of The Drug

Wilate is supplied as a sterile, lyophilized powder for intravenous injection after reconstitution.
Contains von Willebrand Factor and Coagulation Factor VIII complex derived from screened human plasma donations.
Inactive ingredients include glycine, sucrose, sodium chloride, sodium citrate, calcium chloride, water for injection, and polysorbate 80.
The manufacturing process involves cryoprecipitate reconstitution, aluminum hydroxide treatment, chromatography, ultrafiltration, and virus inactivation steps.
Virus inactivation includes solvent/detergent treatment with tri-n-butyl phosphate and Octoxynol-9 followed by dry heat treatment at 100°C for 120 minutes.
Final product is sterile-filtered and packaged aseptically in single-dose vials.
Packaging components are free of natural rubber latex to minimize allergy risk.
Available vial sizes: 500 IU and 1000 IU units to accommodate dosing flexibility.
Reconstitution requires the diluent provided with the vial; aseptic technique is critical.
The reconstituted product should be clear, colorless to slightly yellow, free of particulate matter, and used within 4 hours.
Storage prior to reconstitution is recommended at 2°C to 8°C (36°F to 46°F), with stability up to 36 months from manufacture date.
Wilate may be stored at room temperature (up to 25°C/77°F) for a maximum of six months, but must not be returned to refrigeration after that.
Discard any unused portion as the product is intended for single use to prevent contamination risks.
Users must follow detailed instructions for preparation, administration, and disposal to ensure safety and efficacy.
Manufactured by Octapharma Pharmazeutika Produktionsges.m.b.H. under stringent quality controls.