FDA OKs intentional genomic alteration in pigs — with potential therapeutic applications

The FDA has approved an intentional genomic alteration (IGA) in a line of domestic pigs known as GalSafe. The decision marks the first time the agency has signed off on a biotechnology product for both food applications and potential therapeutic use.

The news “represents a tremendous milestone for scientific innovation,” said FDA Commissioner Dr. Stephen M. Hahn in a statement. “As part of our public health mission, the FDA strongly supports advancing innovative animal biotechnology products that are safe for animals, safe for people, and achieve their intended results.”

The GalSafe pig alteration removes the alpha-gal sugar (galactose-α-1,3-galactose) on the surface of pig cells.

A segment of the population has a mild to severe allergic reaction to this sugar molecule; the reaction is called alpha-gal syndrome. The sugar is found in many mammals, as well as some medications and vaccines.

The GalSafe pigs could be a source of biomaterials for use in individuals with alpha-gal syndrome. Examples include the blood-thinning medication heparin. Surgeons could also potentially use tissues and organs from GalSafe pigs in xenotransplants. The alpha-gal sugar possibly contributes to xenotransplantation rejection.

The genetically modified pigs also have several human genes, including a gene that makes a protein known as CD46 involved in the human immune system.

The prevalence of alpha-gal syndrome (AGS), also known as alpha-gal allergy, is currently unknown, although CDC believes ticks may cause the condition.

FDA also determined that meat from GalSafe pigs is safe for consumption and confirmed that they could not detect alpha-gal sugar in the meat.

GalSafe pigs developer Revivicor, however, did not provide data to FDA indicating that the meat could eliminate or prevent food allergies.

The agency did not evaluate the GalSafe pig line for its potential for xenotransplantation products. Such a use would require the developer to submit an additional application to the FDA.

The company states that it ultimately aims to provide human-compatible cells to treat disease and serve as a source for transplants.

Researchers first developed a genetically modified pig lacking the gene associated with alpha-gal sugar. In experiments, the porcine organs survived for months rather than minutes in nonhuman primates.

The first focus of the product developer will be culinary rather than medical. The vendor plans on selling meat from GalSafe pigs by mail order.

PETA senior vice president Kathy Guillermo released a statement regarding the news. “The genetic manipulation of pigs to serve as interspecies spare-parts bins and more palatable dinner entrées for humans is the apex of arrogance and cruelty,” she said. “Pigs aren’t apples. They’re sentient beings, and fiddling with their genes to produce different varieties that suit our needs and changing tastes is violence, not innovation. Pigs’ genetic material belongs to pigs, and it should be considered inviolate.”

Revivcor is a sister company to PPL Therapeutics, which produced Dolly the Sheep, the first mammal cloned from an adult stem cell.