These GM pigs are being produced in Blacksburg, Virginia, by Revivicor, a division of the biotechnology company United Therapeutics. That company’s founder and co-CEO, Martine Rothblatt, is a noted futurist who four years ago began spending millions to supply researchers with pig organs because one of her daughters has a usually fatal lung condition called pulmonary arterial hypertension.
The problem with xenotransplantation (cross species transplants) is that animal organs set off a ferocious immune response. Even powerful drugs to block the immune attack can’t entirely stop it. All past tests of pig organs have ended quickly, and badly.
To combat these effects, Ayares’s team has made pigs with more and more human genes. While this represents a major breakthrough, it’s important to note that the heart transplants were not life-sustaining but “heterotopic”—the pig heart was attached to the baboon’s circulatory system and was able to beat, but it didn’t have to do the work of pumping blood, since the baboon’s own heart remained in place.