From the Guidelines
Factor 8 deficiency, also known as hemophilia A, is an inherited bleeding disorder caused by insufficient levels of clotting factor VIII in the blood, primarily affecting males and characterized by prolonged bleeding after injuries or surgeries, with severity depending on the amount of factor VIII present 1.
Definition and Characteristics
- Factor 8 deficiency is an X-linked recessive disorder, though females can be carriers.
- People with factor 8 deficiency experience prolonged bleeding after injuries, surgeries, or dental procedures, and may suffer spontaneous bleeding into joints and muscles.
- The severity depends on the amount of factor VIII present, with severe cases having less than 1% of normal levels.
Treatment and Management
- Treatment involves replacing the missing factor VIII through intravenous infusions of factor concentrates, either on-demand when bleeding occurs or as prophylaxis to prevent bleeding episodes.
- Desmopressin (DDAVP) may help in mild cases by temporarily increasing factor VIII levels.
- The standard prophylactic regimen typically involves factor VIII infusions 2-3 times weekly at 25-40 IU/kg per dose, adjusted based on the patient's response 1.
- Modern recombinant factor VIII products have significantly improved quality of life for patients, though some develop antibodies (inhibitors) against replacement therapy, requiring alternative treatments.
- Gene therapy approaches are being developed as potential long-term solutions for this lifelong condition.
Recent Guidelines and Recommendations
- The International Society on Thrombosis and Haemostasis clinical practice guideline for treatment of congenital hemophilia A and B recommends prophylaxis with emicizumab or FVIII concentrate for individuals with severe and moderately severe hemophilia A without inhibitors 1.
- The choice of agent should be guided by availability, resources, costs, values, and preferences.
- In settings where previously untreated individuals with severe hemophilia A will start prophylaxis, the panel suggests initial prophylaxis with plasma-derived FVIII over standard half-life recombinant FVIII 1.
From the FDA Drug Label
Factor VIII is the specific clotting factor deficient in patients with hemophilia A (classical hemophilia). Hemophilia A is a genetic bleeding disorder characterized by hemorrhages, which may occur spontaneously or after minor trauma Factor 8 deficiency is a condition where the body is missing or has low levels of Factor VIII, a clotting factor necessary for blood to clot normally. This deficiency is characteristic of Hemophilia A, a genetic bleeding disorder that can cause hemorrhages to occur spontaneously or after minor trauma. 2
From the Research
Definition of Factor 8 Deficiency
- Factor 8 deficiency, also known as Hemophilia A, is a congenital, recessive, X-linked bleeding disorder caused by a deficiency of clotting factor VIII [ 3 ].
- It is a common hereditary disorder, and the factor VIII gene has been cloned, with a large number of mutations identified that cause Hemophilia A [ 3 ].
Causes and Treatment
- The primary treatment for Hemophilia A is factor VIII replacement therapy, which can be managed with infusions of plasma-derived or recombinant factor VIII [ 4 ].
- However, challenges encountered in the current treatment of Hemophilia A include inhibitor development, which can cause ineffective treatment, morbidity, and mortality among patients [ 5 ].
- Recombinant factor VIII Fc fusion protein is a recombinant fusion protein that undergoes slower clearance from the body than standard half-life FVIII products, allowing for prophylactic administration every 3-5 days or once weekly in selected patients [ 6 ].
Types of Factor VIII Treatments
- There are two types of factor VIII treatments: plasma-derived factor VIII (pdFVIII) and recombinant factor VIII (rFVIII) [ 5 ].
- Studies have shown that rFVIII is associated with a higher risk of overall and high-responding inhibitor development compared to pdFVIII [ 5 ].
- However, rFVIII has been improved over the years to reduce its immunogenicity and enhance its pharmacokinetic behavior [ 7 ].