First Protein Produced by Transgenic Animals Approved

February 12, 2009
Patricia Van Arnum

Patricia Van Arnum was executive editor of Pharmaceutical Technology.

ePT--the Electronic Newsletter of Pharmaceutical Technology

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

Rockville, MD (Feb. 6)-The US Food and Drug Administration issued its first approval for a biological product produced by genetically engineered (GE) animals. The product, “ATryn” (recombinant antithrombin) is an anticoagulant manufactured by GTC Biotherapeutics (Framingham, MA).

ATryn is a therapeutic protein derived from the milk of goats that have been genetically engineered by introducing a segment of DNA into their genes (called a recombinant DNA or rDNA construct) with instructions for the goat to produce human antithrombin in its milk. Antithrombin is a protein that naturally occurs in healthy individuals and helps to keep blood from clotting in the veins and arteries.

GTC Biotherapeutics, the manufacturer of ATryn, received approvals from two FDA centers. The Center for Biologics Evaluation and Research 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.

As part of its review of the GE goat, CVM assessed the safety of the rDNA construct to the animals, including a full review of the construct and its stability in the genome of the goats over seven generations, according to an FDA statement. No adverse outcomes were noted. CVM reviewed and concurred with the sponsor's plan to continue to monitor the construct and its expression for the lifetime of the approved product.

During its review, CVM determined that introduction of the rDNA construct did not cause any adverse outcomes to the health of the goats over seven generations. CVM also determined that the manufacturer, GTC, has adequate procedures in place to ensure that food from these goats does not enter the food supply. As part of the approval, CVM specified that these goats cannot be used for food or feed and validated a method suitable for identifying the rDNA construct in both animals and their products.

As required by the National Environmental Policy Act and its implementing regulations, CVM also determined that the GE goats do not cause any significant impact on the environment, according to FDA.

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 genetically engineered  animals containing heritable rDNA constructs can be found here

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