Potentially opening a new era in farming and pharmaceuticals, the U.S. government has approved the first drug produced by genetically engineered livestock.
The drug, meant to prevent fatal blood clots in people with a rare condition, is a protein extracted from the milk of goats that have been given a human gene.
The same drug, which was approved in Europe in 2006 but has not been widely adopted, is the first to have been cleared by the U.S. Food and Drug Administration under guidelines the agency adopted only last month to regulate the use of transgenic animals in the nation’s drug and food supply.
Made by GTC Biotherapeutics, the drug is produced by a herd of 200 goats that live under quarantine on a high-security farm in central Massachusetts. The animals have been bred to contain a human gene that causes their milk to produce a human blood protein that can be extracted and processed into the anti-clotting drug.
Proponents say such animals could become a way of producing biotechnology drugs at lower cost or in greater quantities than with the existing methods, which involve extracting the drugs from donated human blood or growing genetically engineered cells in steel tanks. The protein in the goat milk, antithrombin, is sometimes in short supply or unavailable for pharmaceutical use because of a shortage of human plasma donations.
GTC Biotherapeutics said one of its goats can produce as much antithrombin in a year as can be derived from 90,000 blood donations. And if more drug is needed, the herd can be expanded.
“If you need more, you breed more,” said Thomas Newberry, a spokesman for GTC, which is based in Framingham, Massachusetts. …
But turning animals into walking pharmaceutical factories does not sit well with some environmental advocates and animal rights activists.
“It is a mechanistic use of animals that seems to perpetuate the notion of their being merely tools for human use rather than sentient creatures,” the Humane Society of the United States says in its position paper on the practice.
There are also more concrete concerns – that the animals could be harmed, that animal germs might contaminate the drug, and that the milk or meat from genetically engineered drug-producing animals might enter the food supply. There is also a concern that such animals might escape and breed with other animals, spreading the gene, with unpredictable consequences.