• XYNTHA is a recombinant antihemophilic factor indicated in adults and children with hemophilia A for on-demand treatment and control of bleeding episodes, for perioperative management, and for routine prophylaxis to reduce the frequency of bleeding episodes. (1)
• XYNTHA is not indicated in patients with von Willebrand's disease. (1)

For intravenous use after reconstitution only (2)

• The required dose is determined using the following formula:
  Required units = body weight (kg) × desired factor VIII rise (IU/dL or % of normal) × 0.5 (IU/kg per IU/dL), where IU = International Unit. (2.1)

Routine prophylaxis (2.1)

• Adults and adolescents (≥12 years): The recommended starting regimen is 30 IU/kg of XYNTHA administered 3 times weekly.
• Children (<12 years): The recommended starting regimen is 25 IU/kg of XYNTHA administered every other day. More frequent or higher doses may be required in children <12 years of age to account for the higher clearance in this age group.
• Adjust the dosing regimen (dose or frequency) based on the patient's clinical response.
• Frequency of XYNTHA administration is determined by the type of bleeding episode and the recommendation of the treating physician. (2.1, 2.2)

XYNTHA is available as lyophilized powder in single-use vials containing nominally 250, 500, 1000, or 2000 IU. (3)

Do not use in patients who have manifested life-threatening immediate hypersensitivity reactions, including anaphylaxis, to the product or its components, including hamster proteins. (4)

• Anaphylaxis and severe hypersensitivity reactions are possible. Patients may develop hypersensitivity to hamster protein, which is present in trace amounts in XYNTHA. Should such reactions occur, discontinue treatment with the product and administer appropriate treatment. (5.1)
• Development of neutralizing antibodies has been reported in patients using XYNTHA. If expected plasma factor VIII activity levels are not attained, or if bleeding is not controlled with an appropriate dose, perform an assay that measures factor VIII inhibitor concentration. (5.2, 5.3, 6.2)

• The most common adverse reactions (≥10%) with XYNTHA in adult and pediatric previously treated patients (PTPs) were headache, arthralgia, pyrexia, and cough. (6)
• Across all studies, 4 subjects developed factor VIII inhibitors (2.4%). (6.2)

To report SUSPECTED ADVERSE REACTIONS, contact Wyeth Pharmaceuticals LLC. at 1-800-438-1985 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch

Pediatrics: Half-lives are shorter, volumes of distribution are larger, and recovery is lower after XYNTHA administration in children. Higher or more frequent dosing may be needed. (8.4)