FDA approves genetically modified pigs to facilitate safer food, medical products for people with allergies
The US Food and Drug Administration (FDA) has approved a genetically modified pig whose body lacks a certain sugar on the surface of their cells — known as alpha-gal — which can trigger allergies in people. The regulatory clearance implies these genetically engineered animals could be safer sources of not just food but also treatments in Americans allergic to the compound.
The pigs are called GalSafe pigs, named for their lack of detectable alpha-gal sugar. According to FDA Commissioner Dr Stephen M Hahn, this “first-ever approval of an animal biotechnology product” for both food and as a potential source for biomedical use represents a “tremendous milestone for scientific innovation.”
“The FDA approved a first-of-its-kind intentional genomic alteration (IGA) in a line of domestic pigs, referred to as GalSafe pigs, which may be used for food or human therapeutics. This is the first IGA in an animal that the FDA has approved for both human food consumption and as a source for potential therapeutic uses.
The IGA in GalSafe pigs is intended to eliminate alpha-gal sugar on the surface of the pigs’ cells. People with Alpha-gal syndrome (AGS) may have mild to severe allergic reactions to alpha-gal sugar found in red meat (such as beef, pork and lamb),” the FDA explained in a statement issued on December 14.
The FDA granted approval of the IGA in GalSafe pigs to Revivicor Inc. The product developer indicated that it initially intends to sell meat from GalSafe pigs by mail order, rather than in supermarkets.
According to the agency, GalSafe pigs may potentially provide a source of “porcine-based materials” to produce human medical products that are free of detectable alpha-gal sugar. GalSafe pigs, for example, may be used as a source of medical products, such as the blood-thinning drug heparin, free of detectable alpha-gal sugar. 
“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. Today’s action underscores the success of the FDA in modernizing our scientific processes to optimize a risk-based approach that advances cutting-edge innovations in which consumers can have confidence,” noted Dr Hahn.
Researchers said that tissues and organs from GalSafe pigs may also be able to address the issue of immune rejection in “patients receiving xenotransplants (transplant between species),” as alpha-gal sugar is believed to be a cause of rejection in patients. The agency, however, cautioned that these pigs have not been evaluated for use as xenotransplantation products for transplantation or implantation into humans. “Developers of any such human medical products must first submit an application to, and obtain approval from, the FDA before these products can be used in human medicine,” they advised.
What scientists evaluated?
As part of its review, the FDA analyzed the safety of the IGA for the animals and people eating meat from them, as well as the product developer’s intention to market the IGA for its ability to eliminate alpha-gal sugar on pigs’ cells. The FDA determined that food from GalSafe pigs is safe for the general population to eat. The FDA’s review focused on ensuring the effectiveness of the IGA through the evaluation of data demonstrating that there is “no detectable level of alpha-gal sugar across multiple generations” of GalSafe pigs.
Scientists evaluated the potential impact that the approval of the IGA in GalSafe pigs would have on the US environment and determined it is no greater than from conventional pigs. The conditions under which GalSafe pigs will be kept are far more stringent than those for conventionally farmed pigs, explained experts. Additionally, no animal safety concerns were noted for GalSafe pigs beyond those that would be expected in well-managed, commercial swine operations.
“The FDA also assessed the risk of the IGA to promote the emergence or selection of antimicrobial-resistant bacteria of human health concern in or on GalSafe pigs. The FDA concluded that the microbial food safety risk is low and is mitigated by the low number of GalSafe pigs entering the food supply and the ongoing surveillance for antimicrobial resistance, among other factors,” the agency said.