NY Times wrote:The newest product made from goat’s milk is not a tangy cheese, but a drug that could prevent fatal blood clots.
Ushering in a new era of both agricultural and pharmaceutical technology, the Food and Drug Administration on Friday approved the first pharmaceutical product made in the milk of genetically engineered animals.
The 200 goats, which are assiduously cared for at a secure farm in central Massachusetts, contain a human gene that causes them to produce a human blood protein in their milk. After the goats are milked, the protein can be extracted for sale as a drug.
Such “pharm animals” as they are sometimes called, could become a way of producing biotechnology drugs at lower cost or in greater quantities than the existing methods, which are to extract them from donated blood or to grow genetically engineered cells in steel tanks.
For instance, the protein being made in the goat milk, antithrombin, is now derived from donated blood plasma. But it is sometimes unavailable because of a shortage of plasma donations.
The production in the goat milk should end such shortages, said GTC Biotherapeutics, the company that developed the animals and the drug. A single goat 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, Mass.
But turning animals into walking pharmaceutical factories does not sit well with some environmental advocates and animal rights advocates.
“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 said in a 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 drug-producing animals might enter the food supply. Another concern is that the goats might escape and breed with other animals, spreading the gene.
The F.D.A. only last month issued final guidelines on how it would regulate genetically engineered animals. In addition to approving GTC’s drug, it approved the goat on Friday, the first animal accepted under the new guidelines.
Other drugs produced in animals are under development. A company called Pharming plans to apply this year for approval of a drug, made in the milk of transgenic rabbits, to treat hereditary angioedema, a protein deficiency that can lead to dangerous swelling of tissues.
Another company, PharmAthene, working under a Defense Department contract, is developing a treatment for nerve gas poisoning in the milk of transgenic goats.
Milk is not the only animal product that might one day yield drugs. Companies have explored making drugs in the eggs of genetically modified chickens and even in the semen of gene-altered hogs.
Still, it is not clear to what extent the use of the animals will catch on. Established manufacturers might stick with the tried-and-true methods. “I think we have very good ways of making therapeutic proteins today,” said Norbert Riedel, chief scientific officer at Baxter International, which makes proteins both from human plasma and in cell culture. One risk of using animals, is that drug production can be lost if a disease wipes out the herd.
Still, GTC and others hope Friday’s approval will eliminate one barrier that stopped companies from producing drugs in animals — the uncertainty over whether the F.D.A. would approve such a drug.
“It really takes away one of the biggest issues that have always been on the table, which is how do regulatory agencies view this kind of technology,” said Samir Singh, president of the American operations of Pharming, which is based in the Netherlands.
Indeed, showing that approval could be obtained is a major reason GTC developed its drug, called ATryn. Sales are expected to be modest. The drug was approved in Europe in 2006 and sales there have been small.
ATryn will be sold in the United States by Ovation Pharmaceuticals. It is not clear what the price will be and how that price will compare to that of the product from human plasma. The drug was approved for people born with a rare hereditary deficiency of antithrombin to prevent blood clots while they undergo surgery or childbirth.
People with the deficiency are vulnerable to blood clots. They can reduce that risk by taking blood thinners like warfarin. But during surgery or child delivery, blood thinners are usually not used because they increase the risk of excessive bleeding.
The F.D.A. determined ATryn was as effective as antithrombin derived from human plasma in preventing clots. But the protein derived from plasma lasts longer in the body than the one from goats, probably because the sugars coating the protein are different
So this is pretty fascinating to me, and honestly I've got no moral qualms about any of this. Do other people feel the same way?