ImageGTC Biotherapeutics and Ovation Pharmaceuticals, Inc. announced that the US Food and Drug Administration (FDA) 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 US. Along with the approval of ATryn, the FDA's Center for Veterinary Medicine also approved GTC's New Animal Drug Application, the first of its kind to regulate genetically engineered animals. This is now required for a recombinant technology used to develop transgenic animals, such as the goats that produce recombinant antithrombin. GTC has granted Ovation the right to market ATryn in the US 1 and pursue further clinical development. The companies expect ATryn to be available in the second quarter of 2009.

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 approval of ATryn marks a significant milestone in the development of this innovative recombinant technology and delivers a new therapeutic option to benefit hereditary antithrombin deficient patients who are undergoing surgery or childbirth procedures," said Geoffrey F. Cox, Ph.D., GTC's chairman and chief executive officer. "Advancing this novel technology from the early days of demonstrating its capability to the daily practice of producing a safe and efficacious product for the US and the European Union, is a testament to the persistence and capability of our employees."

ATryn was developed to provide a safe and consistent supply of recombinant antithrombin.

"With FDA approval of ATryn, we can help ensure that patients with hereditary antithrombin deficiency, a rare clotting disorder associated with severe complications, have access to much needed therapy," said Jeffrey S. Aronin, Ovation president and chief executive officer. "Bringing ATryn to market gives us the opportunity to make a meaningful difference in the lives of people with this rare disorder and is consistent with Ovation's mission of addressing unmet medical needs of small patient populations."

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 US, 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.

The prevalence of hereditary antithrombin deficiency in the general population is approximately one in 2,000 to one in 5,000.4,5 Half these patients may experience a thrombosis before 25 years of age and, based on a study, up to 85 per cent may suffer a thromboembolic event by age 50.

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.

The process for producing ATryn involves scientists inserting DNA for the human antithrombin protein into a single-celled goat embryo. This embryo is implanted into a surrogate doe. The resulting transgenic offspring are able to produce high levels of antithrombin in their milk. This protein is collected and purified from the milk to produce ATryn, which is administered to patients by intravenous infusion.

GTC Biotherapeutics develops, supplies, and commercializes therapeutic proteins produced through transgenic animal technology. In addition to ATryn, GTC is developing a portfolio of recombinant human plasma proteins with known therapeutic properties.

Ovation is a fast growing biopharmaceutical company that develops and commercializes medically necessary therapies to satisfy unmet medical needs for patients with severe illnesses. Headquartered in Deerfield, Illinois, with products available in more than 85 countries, Ovation is committed to having a significant impact on patients' lives through its focus on central nervous system (CNS), haematology/oncology, and hospital-based therapies.