The US Food and Drug Administration has given the thumbs up to a genetically modified chicken that produces a drug in its eggs. It's the latest addition to a growing area in medicine known as "farmaceuticals." The drug is called Kanuma, or sebelipase alfa, and it's used to treat a rare and devastating disease known as lysomal acid lipase deficiency (or LAL deficiency). This heritable condition prevents the body from breaking down fatty molecules in cells, including those in the liver, spleen, and vasculature. Kanuma, a recombinant human enzyme marketed by Alexion Pharmaceuticals, replaces the faulty enzyme responsible for the disorder, which is often fatal in infants. A second form of the disorder also exists in adults, causing liver enlargement, fibrosis, cirrhosis, and cardiovascular disease.
Kanuma can be synthesized in the lab, but now some of that work is being offloaded to chickens. Kanuma is produced by transgenic chickens that have been endowed with a genetic code responsible for producing a critical protein that appears in the whites of their eggs. These egg whites are subsequently refined to extract the compounds that are eventually used to produce the drug.
"LAL deficiency is a rare inherited genetic disorder that can lead to serious and life-threatening organ damage, especially when onset begins in infancy," noted Center for Drug Evaluation and Research (CDER) Director Janet Woodcock in an FDA release. "Using this technology, these patients for the first time ever have access to a treatment that may improve their lives and chances of survival."
It should be stressed that the genetically engineered chickens will only be used to produce the drug; neither the chicken or the egg will be allowed to enter into the food supply. The FDA says the chickens won't escape into the food supply because they're kept indoors. The federal regulator also made sure that the technique wasn't harmful to the chickens, and that their modified DNA was stable across multiple generations.
This isn't the first so-called "animal drug". As Nature News points out, the FDA has already approved GM goats that produce an anticoagulant in their milk, and a drug for treating hereditary angioedema that's produced by transgenic rabbits. [Nature [UPI [FDA]]