Atryn

Human antithrombin III (ATryn ) was the first therapeutic recombinant protein to be produced using a transgenic system... 

THROMBATE III (Bayer) is a plasma-derived product that is used to treat AT-III deficiency, the first inherited trait discovered which was identified in 1965. The condition is associated with thrombophilia caused by low levels of AT-III or the presence of altered AT-III activity. Both conditions can result in excessive blood clotting. Acquired AT-III deficiency is another condition that occurs in situations with high risk of thrombosis such as trauma, burns, and sepsis. GTG Biotherapeutics conducted chnical trials with ATryn in high-risk situations such as surgery or child de-Hvery to prevent deep-vein thrombosis in hereditary AT-III-deficient patients and heparin-resistant patients with acquired AT-III deficiency undergoing coronary bypass. A pharmacokinetic study in patients with hereditary AT-III deficiency indicated that the administration of the recombinant product resulted in an increase in blood... 

AT-III activity which was similar to that seen with the plasma-derived product. Clinical use of ATryn in patients who had surgical procedures indicated that it was well tolerated in all cases. Shortages in THROMBATE III supplier resulted in the use of ATryn on compassionate grounds when the plasma product was not available. No clinical evidence of thrombosis has been reported in any of these compassionate-use patients. The routine use of THROMBATE III as replacement therapy is not generally recommended due to the high cost, the risk of infection, and the need for frequent intravenous administration. The recombinant product derived from milk should have improved safety and reduced cost, resulting in a product that is suitable for chronic use. 

In addition to ATryn , GTC Biopharmaceuticals has several other products under development in collaboration with Cento-cor, Abbott, Elan, Bristol-Myers Squibbs, Alexion, Progenies Pharmaceuticals, Im-munoGen, and Merrimak Pharmaceuticals. These collaborations and internal programs involve the production of several monoclonal antibodies, recombinant human seram albumin, a malaria vaccine, fusion proteins, and a protein for the treatment of autoimmune conditions. Some of the products that are currently undergoing cHnical trials and will be discussed later [361]. 

The success of ATryn may also stimulate the use of transgenic technology for similar replacement therapeutic enzymes... 

The First Biopharmaceutical from Transgenic Animals ATryn ... 

At this point, eight chnical studies have been undertaken with ATryn (Table 11.3). Two clinical indications were pursued ... 

The authors are deeply indebted to their colleagues at GTC Biotherapeutics and Genzyme. The development of a new dmg is truly an enormous endeavor, and entire scientific teams have dedicated years of their professional lives to the filing of ATryn. In addition, the authors extend special thanks to Suzanne Groet, Tom Newberry, and Dick Scotland for their critical reading and constructive suggestions, as well as to Jennifer Williams and Merry Harvey for their generous help with the illustrations. 

Atrial natriuretic peptide (ANP) 290 Atrioventricular block 298 Atriplex gmelini 974 ATryn 29, 855, 995... 

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