FDA Approves Orphan Drug ATryn, First Biologic Developed in Transgenic Animals

The US Food and Drug Administration issued its first approval on February 6 for a biological product produced by genetically engineered animals.

ATryn, manufactured by GTC Biotherapeutics, Inc. (Framingham, MA), is a therapeutic protein derived from the milk of genetically engineered goats milk. Antithrombin is a protein that naturally occurs in healthy individual and helps to keep blood from clotting in the veins and arteries.

GTC received approvals from two FDA centers. The Center for Biologics Evaluation and Research (CBER) approved the human biologic based on its safety and efficacy, and the Center for Veterinary Medicine (CVM) approved the rDNA construct in the goats that produce ATryn.

ATryn is used for the prevention of blood clots in patients with a rare disease known as hereditary antithrombin (AT) deficiency. These patients are at high risk of blood clots during medical interventions, such as surgery, and before, during, and after childbirth.

Because hereditary AT deficiency occurs in a small population (approximately 1 in 5,000 people in the US), the FDA granted ATryn an orphan drug designation. The orphan drug designation system encourages the development of medications for patients with a rare disease or condition.

A summary of the information on which the FDA made its approval decision for the rDNA construct in the goats, and CVM’s guidance on the regulation of GE animals containing heritable rDNA constructs are available at http://www.fda.gov/cvm/GEAnimals.htm.

ATryn previously received approval from the European Medicines Agency for use in preventing clotting conditions during surgical procedures in patients with hereditary AT deficiency.