by Kristen Minogue
Jan 22, 2009

Medication from genetically engineered animals could appear as early as next month if, as anticipated, the Food and Drug Administration approves ATryn, a blood thinner made from the milk of genetically engineered goats.

An FDA committee gave a green light to the drug, manufactured by Framingham, Mass.-based GTC Biotherapeutics, on Jan. 9. The European Commission already approved the drug in August 2006, and the FDA could formally approve it for sale in the U.S. as soon as Feb. 7.

If the agency approved it, the drug could help treat patients with a rare blood-clotting disorder called hereditary antithrombin deficiency.

ATryn is just one of several drugs from gentically engineered animals that could start appearing on the market soon.

“Transgenic animals are probably going to be the drug stores of the future,” said biologist Bryan Pickett, who works with genetically engineered zebra fish at Loyola University of Chicago.

The FDA guidelines for such drugs, released on Jan. 15, outlined a much more stringent review process for genetically engineered animal products than cloned animal products. Unlike clones, which are supposed to be genetically identical to animals that already exist, genetically engineered animals have DNA from other organisms, often other species, inserted into their genome. Milk and meat from cloned cows, pigs and goats received a blanket approval from the FDA in January 2008.

The FDA evaluates every different “recombinant DNA construct “– foreign DNA inserted into an animal – on a case-by-case basis. Developers who want to market products from transgenic animals have to submit a new animal drug application to the FDA. Approval can take up to 10 months.

So far the only genetically engineered animals for sale in the U.S. are a glow-in-the-dark zebra fish sold in pet stores and laboratory animals like mice. The FDA hasn’t received any applications for genetically engineered meat.

Consumers are wary of the new technology. Of the 28,000-plus comments the FDA received on the draft guidelines last fall, the overwhelming majority opposed genetic engineering.

But that isn’t stopping developers, according to University of Illinois at Urbana-Champaign biologist Matthew Wheeler, who co-authored a report on the animals’ potential benefits last June.

Wheeler’s report showed genetically engineered animals are popping up in dozens of sectors, including:

 New Medicines – ATryn may become the first transgenic animal-produced drug to hit U.S. markets, but it’s not the only one that’s been developed. Researchers have created milk from genetically engineered sheep and pigs that can treat a rare type of hemophilia. Another strain of genetically altered pigs secretes milk with a hormone to help anemia patients produce more red blood cells.

 Eco-friendly Animals – Researchers created the Enviropig in 2001, a pig that can excrete 60 percent less phosphorus than normal pigs, reducing pollution. Scientists at the National University of Singapore engineered the GloFish, a fluorescent zebra fish now sold in the U.S., to detect water pollution.

 Human-Animal Transplants – Some have greeted this as the solution to the organ shortage problem. Transgenic pig hearts have lasted in baboons for up to six months. Researchers also hope insulin-producing pig cells could help diabetes patients and transgenic pig livers could act as temporary transplants while patients wait for permanent replacements.

 Animal Health – Genetically engineered dairy cows are already able to begin resisting mastitis, an infection that decreases milk production, by secreting the bacteria-killer lysostaphin into their milk. Other possibilities include creating cows resistant to mad cow disease and brucellosis, a bacterial disease that can be transferred to humans.

Pickett said the risk of releasing potentially dangerous genetic materials is very low. But at the same time he respects the FDA’s regulation.

Meanwhile researchers are trying to calm any fears consumers may have about genetic engineering.

“I think all scientists really are for responsible, compliant and responsible, drug policy,” Pickett said.