GalSafe pigs: FDA approves first genome-altered animal for human consumption

15 Dec 2020 --- The US Food and Drug Administration (FDA) has approved the first intentional genomic alteration (IGA) in an animal for human consumption with GalSafe pigs.

The FDA granted approval of the IGA to the regenerative medicine company Revivicor, which intends to sell meat by mail order, rather than supermarkets.

Eliminating alpha-gal sugar
The IGA in GalSafe pigs is intended to eliminate alpha-gal sugar on the surface of the pigs’ cells, a substance that people with alpha-gal syndrome (AGS) may have a mild to severe allergic reaction to.

The elimination of the sugar, which also appears in beef and lamb, suggests that the animal may be safer to eat for some populations.

However, the FDA’s review process did not evaluate food safety specific to those with AGS, as the application did not include data regarding the elimination or prevention of food allergies. 

The line of pigs is also poised to produce human medical products such as the blood-thinning drug heparin and decrease the risk of immune rejection in transplants. 

“Today’s 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,” says FDA Commissioner Stephen Hahn. 

Potential risks
While the move may be hailed as an advancement, recent studies have expressed concern that quickly moving technology may have a greater impact than we are aware of. 

The emergence of antimicrobial resistance due to GalSafe pigs has been deemed “highly unlikely” in the FDA’s safety evaluation.In the FDA’s evaluation of the GalSafe pigs, the emergence of antimicrobial-resistant bacteria was highlighted as a potential threat via the release of the nptII gene and NPTII protein into nature. 

However, this would only be a risk if the pigs escaped, which does not constitute “exposure,” according to the National Research Council, and was “highly unlikely” to occur. 

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.

Testing across generations
The FDA has evaluated the safety for the animals and people eating meat from them and determined that food from GalSafe pigs is safe for the general population to eat. 

The FDA’s review also examined data across multiple generations of GalSafe pigs, which demonstrated no detectable level of alpha-gal sugar. 

The environment was also factored into the safety evaluation and the altered pigs were determined to be no greater threat to the environment than conventional pigs, who would similarly destroy crops if they escaped and turned feral. 

From GE to IGA
The FDA first issued draft guidance on the regulation of genetically engineered (GE) animals and their products in 2008.

The agency used the term “GE” to describe the animals within the scope of that guidance to reflect the technology in use at the time. Because IGAs now can also be produced through newer technologies, the more inclusive term IGA is used.

The FDA highlights that the key difference between genetic engineering and genome editing is the precision. Genome editing is the intentional addition, substitution or deletion of specific nucleotides (letters in the DNA code) in an organism’s genome.

By contrast, genetic engineering allows for the introduction of new DNA but generally without control of the location in the genome in which the insertion of that rDNA construct would occur.

By Missy Green