FDA Approves ATryn

The U.S. Food and Drug Administration (FDA) has approved ATryn (Antithrombin [Recombinant]) for the prevention of peri-operative and peri-partum thromboembolic events in hereditary antithrombin deficient patients. It is not indicated for treatment of thromboembolic events in hereditary antithrombin deficient patients.

ATryn is the first ever transgenically produced therapeutic protein and the first recombinant antithrombin approved in the U.S.

People with hereditary antithrombin deficiency are at increased risk for venous thromboembolic events, including pulmonary embolism and deep vein thrombosis, which can be life-threatening, particularly in high risk situations. Antithrombin is a natural anticoagulant that plays an important role in controlling the formation of blood clots. Purified recombinant antithrombin has the same amino acid sequence as antithrombin derived from human plasma.

The safety and efficacy of ATryn was established in clinical studies conducted in hereditary antithrombin deficient patients with a history of thromboembolic events in the U.S., Europe and Canada. During these studies, ATryn was shown to prevent the formation of clinically overt thromboembolic events. Post-marketing studies will be performed to assess safety and immunogenicity after repeat dosing.

About ATryn

ATryn is the first recombinant antithrombin product approved in the world and the first antithrombin product that has been approved through the centralized procedure in the European Union. It is now also the first recombinant antithrombin product approved by the FDA.

ATryn is contraindicated in patients with known hypersensitivity to goat and goat milk proteins. Allergic-type hypersensitivity reactions, including anaphylaxis are possible. If these reactions occur during administration, treatment must be discontinued immediately and emergency treatment should be administered.

The anticoagulant effect of drugs that use antithrombin to exert their anticoagulation may be altered when ATryn is added or withdrawn. To avoid excessive or insufficient anticoagulation, coagulation tests suitable for the anticoagulant used (e.g., aPTT and anti-Factor Xa activity) are to be performed regularly, at close intervals, and in particular in the first hours following the start or withdrawal of ATryn. Additionally, patients must be monitored for the occurrence of bleeding or thrombosis in such situations.

The serious adverse reaction that has been reported in clinical studies is hemorrhage (intra-abdominal, hemarthrosis and post procedural). The most common adverse events reported in clinical trials at a frequency of = 5% are hemorrhage and infusion site reaction.

Most common adverse reactions reported in clinical trials at a frequency of = 5% were hemorrhage and infusion site reaction.

To report suspected adverse reactions, contact Ovation Pharmaceuticals at 1-800-455-1141 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Drug Interactions

• ATryn enhances anticoagulant effect of heparin and low molecular weight heparin.
• The half-life of ATryn may be altered by concomitant treatment with anticoagulants that use antithrombin to exert their anticoagulant effect.

Use in Specific Populations

• Pregnancy Category C. Studies in pregnant women have not shown that ATryn increases the risk of fetal abnormalities if administered during the third trimester of pregnancy. No data is available for use of ATryn in earlier stages of pregnancy.
• Labor and Delivery: ATryn is used in the treatment of peri-partum women with hereditary antithrombin deficiency.
• Nursing Mothers: ATryn administered by infusion will be present in breast milk at estimated concentrations 1/50 to 1/100 that of concentration in blood. Use only if clearly needed.