First rDNA construct approved for human use

A human-use anticoagulant derived from milk of genetically engineered goats is the first approved pharmaceutical product of a genetically engineered animal.

The Feb. 6 approval for rhAT (trade name ATryn), which is used to prevent blood clots in patients with a rare hereditary condition, came 22 days after the Food and Drug Administration issued a guide for industry on the regulation of genetically engineered animals. The final guidance document asserted the FDA's authority in regulating such products.

The recently approved anticoagulant, which was developed by GTC Biotherapeutics, is approved for use in patients with hereditary antithrombin deficiency. About one in 5,000 people in the United States has the condition, and they are particularly at risk of life-threatening blood clots during surgery and childbirth, according to the FDA.

Prior to approval of the recombinant antithrombin, patients relied on antithrombin derived from human blood plasma.

A statement from GTC Biotherapeutics says the product was approved for use in the European Union in summer 2006.

The FDA final guidance document details the agency's view of its jurisdiction in regulations on genetically engineered animals and provides the framework for those products to reach consumers.

Also known as Guidance for Industry #187, the document includes nonbinding recommendations for industry and language that describes genetic modifications as "new animal drugs." It says existing regulations give the agency authority over "articles intended for use in the diagnosis, cure, mitigation, treatment or prevention of disease in man or other animals" and articles other than food "intended to affect the structure or any function of the body of man or other animals."

Genetically engineered animals have to be approved by the FDA prior to distribution, and the document includes recommendations on the types of information producers can supply to gain approval for sales.

The final guidance includes few substantial changes from a draft document released in September 2008. One change is the addition of two paragraphs that state the FDA intends to increase transparency of deliberations and actions by holding public advisory committee meetings prior to approval of genetically engineered animals.

The document notes the FDA could revisit the policy of holding such meetings in the future.

About 28,000 of the nearly 29,000 comments received by the FDA by mid-December were form letters, most of which expressed opposition to genetic engineering of animals, according to information from the FDA. About 60 of the remaining 797 comments contained substantive comments with "detailed analyses, recommendations, or opinions."

The FDA's responses to those comments, the guidance document, and additional information about genetically engineered animals are available at fda.gov/cvm/geanimals.htm.