February 16, 2009
This February is an exciting month for the company GTC Biotherapeutics and the future of the biotechnology of preventing blood clots. It is a groundbreaking moment for the science of making therapeutic proteins produced through transgenic animal technology. The first genetically engineered animal approved for commercial use in the U.S. by the FDA is not a fast growing salmon as was originally expected, but a milk producing, transgene-protein-producing four legged goat!
These goats, living on a farm in Massachusetts, are programmed to produce a needed medicine by either injecting pre-packaged DNA into an embryo which then grows into a goat, or by injecting the DNA directly into an adult goat cell. Either way, the end result is an animal that produces Atryn - a protein known as anti-thrombin.
The US is a little bit behind the times when it comes to goat gene manipulations. The drug (made from this same farm in Mass.) was approved for use in Europe 2 years ago.
Anti-thrombin deficiency is a significant problem. About 1 in 3,000-5,000 people are born with the genetic defect that prevents them from making enough of this protein - which prevents blood clots from forming too easily. Lack of this protein can lead to strokes or blood clots in the legs or lungs, esp. during surgery or childbirth, which is when Atryn is usually given.
The larger implications of this process are for the production of drugs that are needed in large quantities or for rare diseases where drugs are extremely expensive to produce by more traditional methods. Other products are being targeted for people with hemophilia, severe respiratory disease, and swollen tissues.
Genetic modification and manipulation of animals for human uses are far from the same thing as embryonic stem cell research, which as my readers now has been somewhat controversial because it utilizes embryos that have the potential to become viable fetuses.
In contrast, Genetic modification of animals to make a lifesaving human medication is a very promising area of research with little downside. These animals are also very isolated on their Massachusetts farm. Their chances of entering the food chain is quite remote.
Marc Siegel, MD, is an internist and professor of medicine at New York University and the author of False Alarm: The Truth About the Epidemic of Fear