Vonvendi điều trị bệnh Von Willebrand: Công dụng, liều lượng và tác dụng phụ.

Vonvendi is a prescription medicine used to treat and control bleeding episodes in people with bệnh von Willebrand (VWD). It is also used to manage bleeding around surgery, and in adults, it can be used routinely to reduce the frequency of bleeding episodes.  VWD is an inherited bleeding disorder in which the blood does not clot properly.  As a result, people with VWD experience bleeding for longer than normal after injuries, surgeries, dental procedures, or other situations. VWD is the most common inherited bleeding disorder and affects about 1% of the U.S. population [1]. 

If you or someone you care for is living with von Willebrand disease (VWD), treatments are available to help manage bleeding. Vonvendi is one treatment option that can help control bleeding episodes and, in certain situations, help prevent excessive bleeding. In this article, we’ll discuss Vonvendi, including its uses, side effects, dosage, precautions, and cost. 

What Is Vonvendi?

Vonvendi is an FDA-approved recombinant von Willebrand factor (VWF) medicine. In adults and children with von Willebrand disease (VWD), it is used for on-demand treatment and control of bleeding episodes and for perioperative management of bleeding. In adults, Vonvendi is also approved for routine preventive treatment (prophylaxis) to reduce the frequency of bleeding episodes [3]. 

The FDA first approved Vonvendi in the United States in 2015 [2]. Unlike plasma-derived VWF products, such as Humate-P, Vonvendi contains recombinant VWF and is not derived from human plasma [3]. 

Vonvendi comes as a powder that is mixed with sterile water before it is given as an intravenous (IV) injection. 

What Is Vonvendi Used For?

Vonvendi is FDA-approved for certain uses in adults and children with von Willebrand disease (VWD), although not all approved uses apply to both age groups [3]. Vonvendi contains a recombinant version of VWF, a protein that plays an important role in blood clotting. It temporarily replaces deficient or dysfunctional VWF in people with VWD. Vonvendi is FDA-approved for [3]:

On-Demand Treatment and Control of Bleeding Episodes: People with VWD can use Vonvendi when they experience bleeding that requires replacement of von Willebrand factor (VWF). Depending on the severity and location of the bleeding, you may need several doses.

Management of Bleeding Around Surgery:  Vonvendi can be used before, during, and after surgery to help manage bleeding. 

Routine Preventive Treatment of Bleeding: Adults with VWD can receive Vonvendi regularly as routine prophylaxis to reduce the frequency of bleeding episodes [3]. 

Please note that Vonvendi does not cure von Willebrand disease (VWD). Instead, it temporarily replaces the missing or defective VWF and helps your body control bleeding.

How Does Vonvendi Work?

People with von Willebrand disease (VWD) either have too little von Willebrand factor (VWF) in their blood or have VWF that does not work properly. Vonvendi contains a man-made version of VWF. It works by temporarily replacing the missing or ineffective VWF.

VWF has two important roles in forming a blood clot. First, VWF helps platelets attach to sites where blood vessels have been damaged, an important step in forming a blood clot. Second, VWF binds to factor VIII and protects it from being broken down too quickly in the bloodstream. 

By providing recombinant VWF, Vonvendi increases VWF activity in the blood and can also help stabilize the patient’s own factor VIII. If a patient’s baseline factor VIII activity (FVIII:C) is below 40% or is unknown and an immediate increase in FVIII:C is needed, the first dose of Vonvendi should be administered with an approved recombinant factor VIII (rFVIII) product. If an immediate increase in FVIII:C is not necessary, Vonvendi may be administered without rFVIII. Treatment decisions should be based on the patient’s factor levels and clinical situation [3]. 

Vonvendi Side Effects

Like other medicines, Vonvendi can cause side effects. Some side effects may require medical attention. Here are some common and serious side effects of Vonvendi [3][4]:

Tác dụng phụ thường gặp

• Đau đầu
• Nôn mửa
• Buồn nôn
• Chóng mặt
• Ngứa

Talk with your healthcare provider if you experience side effects that persist, worsen, or concern you. 

Tác dụng phụ nghiêm trọng 

Vonvendi can cause serious adverse reactions. Important risks and warnings include hypersensitivity reactions, thromboembolic events, and the development of neutralizing antibodies (inhibitors) [3].  

Phản ứng quá mẫn: Severe allergic reactions, including anaphylaxis, can occur with Vonvendi. Signs and symptoms may include hives, generalized itching, swelling, difficulty breathing, rapid heartbeat, chest tightness, dizziness, or low blood pressure. Stop the infusion and seek immediate medical attention if signs of a severe allergic reaction occur [3]. 

Blood Clots (Thromboembolic Events): Blood clots in arteries or veins have occurred in patients receiving Vonvendi, particularly in people with risk factors for thrombosis. Your healthcare provider may monitor you for signs of blood clots and may also monitor factor VIII levels when Vonvendi is given with recombinant factor VIII. Seek prompt medical attention for symptoms such as chest pain, shortness of breath, or pain or swelling in an arm or leg [3]. 

Development of Inhibitors: Neutralizing antibodies (inhibitors) against VWF and/or factor VIII can develop during treatment. If expected VWF activity or factor VIII levels are not achieved, or if bleeding is not controlled with an appropriate dose, your healthcare provider may perform tests for inhibitors [3]. 

Please note that this is not a complete list of all possible side effects. Contact your doctor immediately if you experience any severe side effects of Vonvendi.

Vonvendi Dosage 

Vonvendi comes as a powder that is reconstituted before administration and is given intravenously. Dosing is individualized according to factors such as body weight, the type and severity of bleeding, the clinical situation, and VWF and factor VIII levels. Your healthcare provider will determine the appropriate dose and treatment schedule. The following summarizes dosing recommendations from the prescribing information [3]: 

For On-Demand Treatment and Control of Bleeding Episodes: For minor bleeding, such as a nosebleed or oral bleeding, the recommended initial dose is 40–50 IU/kg. Subsequent doses of 40–50 IU/kg may be administered every 8–24 hours as clinically required.

For major bleeding, the recommended initial dose is 50–80 IU/kg. Subsequent doses of 40–60 IU/kg may be administered every 8–24 hours for approximately 2–3 days, or as clinically required [3].

Đối với phẫu thuật: Perioperative dosing is individualized according to the type of surgery and the patient’s VWF and factor VIII levels. For elective surgery, a preoperative dose of Vonvendi may be given 12–24 hours before surgery when needed to allow the patient’s factor VIII level to increase. VWF and factor VIII levels are assessed before surgery, and an additional dose may be administered within 1 hour before the procedure to achieve appropriate target levels. Emergency surgery and postoperative dosing require individualized management based on factor levels and clinical response [3]. 

For Routine Preventive Treatment: The recommended dose for adults is 40–60 IU/kg twice weekly [3]. 

Before Starting Vonvendi

Before you start Vonvendi, tell your doctor your complete medical history, including if you [4]:

• Have previously had an allergic reaction to Vonvendi or any of its ingredients
• Have a history of blood clots or other risk factors for thrombosis 
• Have heart or blood vessel problems
• Have previously developed inhibitors or antibodies against VWF or factor VIII 
• Đang mang thai, dự định mang thai hoặc đang cho con bú
• Take any medicines, vitamins, or herbal supplements
• Have previously received other VWF or factor VIII products

Your doctor may monitor your VWF and factor VIII blood levels during treatment to make sure the medicine is working and to reduce the risk of excessive clotting.

Vonvendi Cost

The cost of Vonvendi can vary considerably depending on the prescribed dose, body weight, number and strength of vials required, frequency and duration of treatment, insurance coverage, and where treatment is received.

Because Vonvendi dosing is weight-based and treatment requirements differ among patients, the cost of an individual treatment episode can also vary substantially. For example, patients being treated for a major bleeding episode may require different doses and a different number of infusions than patients receiving treatment for a minor bleed or routine prophylaxis.

The amount a patient pays out of pocket may differ from the medicine’s list or acquisition price because of insurance benefits, deductibles, copayments, and financial assistance programs. Patients should contact their insurance provider, specialty pharmacy, treatment center, or the manufacturer’s patient-support program for current information about coverage and potential out-of-pocket costs. If costs are a concern, liên hệ với chúng tôi to explore financial or copay assistance for Vonvendi.