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ATryn Antithrombin (Recombinant) Prevents Venous Thromboembolic Events in Pregnant Patients with Hereditary Antithrombin Deficiency

FRAMINGHAM, Mass.--(BUSINESS WIRE)--Feb 15, 2013 - rEVO Biologics announced today the results of a major retrospective study analysis of its pivotal phase 3 studies which demonstrate that pregnant patients with hereditary antithrombin deficiency (HD) benefit from ATryn Antithrombin (Recombinant) therapy to prevent venous thromboembolic events (VTE).

Presented as a poster at the February 2013 meeting of the Society for Maternal-Fetal Medicine (SMFM), this integrated analysis was led by Dr. Michael Paidas, professor at Yale School of Medicine and co-director of the Yale Women and Children's Center for Blood Disorders. “This represents the largest known cohort of pregnant patients with HD treated with antithrombin for the prevention of VTE during a high-risk situation,” Dr. Paidas commented.

HD is a blood disorder that affects between one out of every two to five thousand Americans. People with hereditary AT deficiency have a twenty-fold higher risk for VTE events throughout their lifetime. Women with HD are at high risk for VTE during pregnancy and after delivery.

The purpose of the study was to assess the safety and efficacy of ATryn based on pooled data from pregnant AT-deficient women who were enrolled in two phase 3 clinical trials conducted in 28 sites across the United States, Europe, Canada, and Australia. Dosing began up to 24 hours before scheduled Cesarean delivery or on admission for labor and continued for 3 to 14 days. Patients were assessed for the incidence of VTE and adverse events (AEs).

Results of the retrospective analysis showed that no confirmed VTEs were reported between initiation and 7 (±1) days after discontinuation of ATryn therapy. Reported AEs were similar to those expected in pregnant patients during and immediately after delivery. No AEs related to ATryn therapy were reported in the neonates. The study concluded that therapy with ATryn, administered via a bolus loading dose followed by maintenance infusion, is safe and effective for use in pregnant patients with HD.

According to Dr. Simon Lowry, Vice President of Medical Affairs at rEVO Biologics, “This study continues to underscore the important role of ATryn in the management of pregnant patients with hereditary antithrombin deficiency. rEVO Biologics is committed to develop new therapies for patients with rare diseases.”

About rEVO Biologics
rEVO Biologics ( is a rare disease company focused on developing and delivering first and next-generation therapeutics that are more cost effective to produce than traditional recombinant therapies. Through its proprietary rPRO Technology platform - a scalable, transgenic, and cost-effective method of protein production - rEVO Biologics is bringing safe and reliable therapeutic proteins to address critical medical needs. The company's lead product, ATryn is the first and only plasma-free antithrombin concentrate. ATryn received FDA approval in 2009. The company has a number of products in its pipeline and in clinical trials in the areas of hematology, oncology, genetic disorders and autoimmune disease, and is actively seeking additional indications for its lead product.

Indications and Usage
ATryn is a recombinant antithrombin indicated 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.

Important Safety Information
ATryn is contraindicated in patients with known hypersensitivity to goat and goat milk proteins. Allergic-type hypersensitivity reactions, including anaphylaxis, are possible. Patients must be closely monitored and carefully observed for any symptoms throughout the infusion period. Patients should be informed of the early signs of hypersensitivity reactions including hives, generalized urticaria, tightness of the chest, wheezing, hypotension, and anaphylaxis. If these symptoms 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 should 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.

For more information, please view full Prescribing Information for ATryn, visit or call 1-800-610-3776.

To report suspected adverse reactions contact GTC Biotherapeutics at 1-800-610-3776 or the FDA at 1-800-FDA-1088 or


Contact: For rEVO Biologics
Holly Grimshaw, 508-620-9700


Posted: February 2013