The GalSafe pig does not contain a molecule that causes severe allergies. It could be used to make drugs, be a reservoir for human organs, or be used to make allergenic foods and cosmetics.
The United States Food and Drug Administration (FDA) has just approved the first genetically engineered pig for human food and medical use. The pig, called GalSafe and produced by United Therapeutics, will not only be able to be consumed as meat but will also be used for the production of pharmaceutical products or for the production of replacement organs.
The GalSafe pig has a gene that eliminates the presence of a sugar molecule called galactose-α-1,3-galactose (Alpha-gal). This molecule, found in many mammals (but not humans), can cause allergies in some people and causes the body to reject animal transplants.
Since humans do not have Alpha-gal, they cannot tolerate organ xenografts from pigs. Indeed, for heart valves, lungs, liver, kidney, or tendons, the animal would be the best supplier. Humans however produce anti-alpha antibodies (IgG) that cause acute rejection.
Therapeutic products, organ substitutes, and allergenic meat
Therefore, we can understand the interest in these genetically modified pigs. United Therapeutics’ first goal is to develop medical products, such as anticoagulants (heparin), that do not cause allergies. additionally, the company wants to develop organs that are compatible with the human body. In November, XenoTherapeutics launched a Phase 1 trial of GalSafe porcine skin grafts for the treatment of severe burns.
Although additional approvals are required, commercialization of the meat is also being considered. The FDA stated that it has not evaluated the allergy prevention potential of this meat, but only certified that it is safe for human consumption.
Other genetically modified animal products
The FDA has approved genetically modified animal products before. In 2009, for example, it approved an anticoagulant protein produced by modified goats. In 2015, regulators also approved chickens to produce a special enzyme. That same year, AquAdvantage salmon, which grows twice as fast, was approved. However, the GalSafe pig is the first animal certified for food and medical purposes.
However, you shouldn’t expect these pigs to flood supermarket shelves and laboratories. Currently, only 25 GalSafe pigs are raised on one farm in Iowa, and it’s unlikely they will go into mass production as conventional pigs. Furthermore, Alpha-gal is not the only cause of xenograft rejection. It is likely that further genetic modifications will be required in the pigs to develop fully compatible organs for transplantation to humans.