If the European Medicines Agency says “yes” on Thursday, Atryn, a natural human protein extracted from the milk of goats will become the world’s first medicine to be produced from a genetically modified animal.
A decade and a half ago, GTC Biotherapeutics scientists copied the human antithrombin -an anticoagulant, usually extracted from blood plasma- gene and attached it to a chunk of goat DNA, the promoter for beta casein. This gives the instruction to express that gene only in milk and no where else in the body.

The composite was injected into a goat egg, the embryo was then implanted into a surrogate mother and six months later the herd founder was born.
Potential recipients of Atryn are born missing one copy of the anti-thrombin gene, resulting in underproduction of this protein and leaving them prone to blood clots.
“Yes we do need to think about risk of disease transmission from animals, but we already use direct animal products such as heparin from pig tissue and leech extracts for blood thinning, without causing harm to people”, explains Dr Beverley Hunt of St Thomas’ hospital London.
GTC’s Atryn goats are not alone in this novel science. The company is also growing goats producing a treatment to shrink solid tumours.
Dutch firm Pharming keep cows expressing human lactoferrin – a protein found in breast milk which has anti-bacterial qualities and they are also milking rabbits for a treatment for hereditary angioedema, which leads to swelling in various parts of the body.
Life-saving goats, cows, rabbits – it’s a long way from the laboratory mice that were the first living transgenic drug factories in 1987. At the time, human therapeutic proteins produced in animal milk appeared to offer great economic potential. However, not a single product has made it to market yet.
Via BBC News.
Related: Utility Pets.
UPDATE: the application to license the medicine produced from a GM goat has been turned down.