These highlights do not include all the information needed to use XYNTHA ® safely and effectively. See full prescribing information for XYNTHA ®.
XYNTHA ® (antihemophilic factor [recombinant]) lyophilized powder for solution, for intravenous injection
Initial U.S. Approval: 2008 RECENT MAJOR CHANGES
XYNTHA is a recombinant antihemophilic factor indicated in adults and children with hemophilia A for control and prevention of bleeding episodes and for perioperative management. (1)
XYNTHA is not indicated in patients with von Willebrand's disease. (1)
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.
Frequency of XYNTHA administration is determined by the type of bleeding episode and the recommendation of the treating physician. (2.1, 2.2)
DOSAGE FORMS AND STRENGTHS
XYNTHA is available as lyophilized powder in single-use vials containing nominally 250, 500, 1000, or 2000 IU. (3) CONTRAINDICATIONS
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) WARNINGS AND PRECAUTIONS
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 activity-neutralizing antibodies has been detected in patients receiving factor VIII-containing products, including 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)
ADVERSE REACTIONS
The most common adverse reactions (≥ 10%) with XYNTHA in adult and pediatric PTPs were headache, arthralgia, pyrexia, and cough. (6)
Across all studies, 3 subjects developed factor VIII inhibitors (2.1%). (6.2)
To report SUSPECTED ADVERSE REACTIONS, contact Wyeth Pharmaceuticals Inc. at 1-800-438-1985 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch
USE IN SPECIFIC POPULATIONS
Pregnancy: No human or animal data. Use only if clearly needed. (8.1)
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)
See 17 for PATIENT COUNSELING INFORMATION and FDA-approved patient labeling.
Sections or subsections omitted from the full prescribing information are not listed.
1 INDICATIONS AND USAGE
XYNTHA, Antihemophilic Factor (Recombinant), is indicated for use in adults and children with hemophilia A (congenital factor VIII deficiency) for:
Control and prevention of bleeding episodes
Perioperative management
XYNTHA does not contain von Willebrand factor, and therefore is not indicated in patients with von Willebrand's disease.
2 DOSAGE AND ADMINISTRATION
For intravenous use after reconstitution only.
2.1 Dose
Initiate treatment with XYNTHA under the supervision of a physician experienced in the treatment of hemophilia A.
Dosage and duration of treatment depend on the severity of the factor VIII deficiency, the location and extent of bleeding, and the patient's clinical condition. Titrate the administered doses to the patient's clinical response.
One International Unit (IU) of factor VIII activity corresponds approximately to the quantity of factor VIII in one milliliter of normal human plasma. The calculation of the required dosage of factor VIII is based upon the empirical finding that, on average, 1 IU of factor VIII per kg body weight raises the plasma factor VIII activity by approximately 2 IU/dL.2
The expected in vivo peak increase in factor VIII level expressed as IU/dL (or % normal) can be estimated using the following formulas:
Dosage (International Units) = body weight (kg) × desired factor VIII rise (IU/dL or % of normal) × 0.5 (IU/kg per IU/dL)
A guide for dosing XYNTHA for the control and prevention of bleeding episodes is provided in Table 1. Maintain the plasma factor VIII activity at or above the levels (in % of normal or in IU/dL) outlined in Table 1 for the indicated period.
Table 1: Dosing for Control and Prevention of Bleeding Episodes
