Pharmaceuticals on GM Animals

The ability to genetically modify animals in order to produce valuable proteins such as pharmaceuticals in their milk has been one of the most innovative applications of the genetic engineering techniques. Pioneered at the Roslin Institute and PPL Therapeutics, it has now been applied to cattle, sheep and goats in order to produce a variety of different proteins. The leading example, now in the last phase of clinical trials, is alpha-1-antitrypsin (AAT) for treating lung diseases emphysema and cystic fibrosis. It is produced in the milk of sheep by adding the human gene which codes for the protein in humans. A related area of research is in genetically modifying poultry to produce pharmaceuticals in the eggs.

The 1997 Assembly report on cloning acknowledged that this did not raise undue ethical problems. The use of sheep milk is traditional and therefore to produce a particular protein in the milk would not seem an undue departure from the current situation, particularly since the sheep version of AAT is produced by the animal, albeit in the liver rather than in milk. The intervention in the animal is judged to be small, the human medical need being addressed is considerable, and other routes to the protein are much more difficult. Indeed, it could be argued as a genuine partnership, in which humans give especial husbandry and care of the sheep in exchange for a valuable product in the sheep's milk. No welfare concerns have arisen from this particular example.In general this is an area where we would say "Yes, provided." One such proviso arose in research to produce a more active protein erythropoietin showed unacceptable welfare effects for the animals, which led to the trials rightly being terminated.