In a green valley, behind a high fence, David Ayares and his teams raise genetically modified pigs to one day sell – for up to a million US dollars – their organs to human patients who need them.
Research on xenografts – transplantation from animals to humans – is progressing very quickly in the United States. And it was one of the pigs from this laboratory farm, located in the mountains of the east of the country, which provided the kidney transplanted to patient Towana Looney in November during an operation announced on Tuesday, a new trial after several world firsts.
“These are not just any farm pigs,” notes David Ayares, boss of the Revivicor company, in his sanitized pigsty. “Millions of dollars were spent” to achieve this modified genome and avoid rejection by the human body, this tall guy told AFP, pink piglets in his arms.
For more than 20 years, his company has been conducting research in Blacksburg, Virginia, to take xenotransplantation out of science fiction and prove that transplanting pig kidneys (or hearts) in place of human organs is not only possible, but would even be the solution to respond to an immense shortage.
In the United States alone, more than 100,000 people are waiting for donations, and 17 of them die every day without having been able to benefit from an organ, most often a kidney, according to health authorities.
Pipette
To answer this, several American surgeons have since 2021 transplanted kidneys and hearts from genetically modified pigs into humans. The first trials were carried out on brain dead people, before a handful of seriously ill patients benefited.
They died one to two months after the operation, but the organs were not immediately rejected by the recipient, a success which opens the way to clinical studies.
Apart from at least one transplant produced by the company eGenesis, most of the organs came from the Revivicor experimental farm.
Nearby, in a darkened lab room, Todd Vaught, Revivicor’s cell biology manager, stares at the microscope. With a pipette, he manipulates oocytes from non-GMO sows collected in the slaughterhouse.
The objective of the day: remove their genetic material then replace it with a cloned cell “which has all the necessary instructions to make a genetically modified pig,” explains Todd Vaught.
A few hours later, these cells are inserted into the uterus of the surrogate sows who will give birth four months later to a litter of piglets with edited DNA.
The first pig line developed by Revivicor carries only one genome edit. This makes it possible to inactivate the pig’s production of a substance which causes immediate rejection of the transplanted organ in humans.
The second involves ten modified genes, six of which come from human DNA in order to improve biological compatibility.
AFP
Organs “harvested”
It is with this second line of pigs that United Therapeutics (UT), the parent company of Revivicor, is thinking big.
This publicly traded company opened a “pharmaceutical factory that runs on pigs” in March, in the words of spokesman Dewey Steadman. He insists on draconian health measures intended to avoid any infection in the 200 animals raised here.
At the end of a white corridor, a brand new operating room. “The pork is going to come here,” Dewey Steadman told AFP. “The organs will be harvested” and transported urgently “to the surgeon and the recipient patient”, as for a human-to-human transplant.
The rest of the killed pig, deemed unusable, will be thrown away.
The company’s objective is to begin a clinical study in 2025 on patients with kidney transplants extracted from these pigs, for possible marketing from 2029 if the American drug agency, the FDA, gives its approval. .
Already anticipating an authorization, Revivicor/UT plans real industrialization, with the construction of factory farms costing one to two billion US dollars per unit, ten times larger than the one barely completed near Blacksburg.
A bet that could pay off big: UT is considering a sale price of around $1 million per kidney — which is close to the cost of ten years of dialysis in the United States, according to Dewey Steadman.
A “model” which questions the French sociologist Catherine Remy, author of “Hybrides”, a recent book on the issue.
She raises with AFP the paradox between the human-animal “proximity” implied by the transfer of organs from one to the other and this American “industrialization” “based on a perception of the animal donor as +stock of spare parts+”, battery farming “objectivizing” the living being which nevertheless provides a kidney or a heart to man.
But in his laboratory, David Ayares sweeps away this ethical question. “I believe that a pig used for its organs for xenograft purposes is a much nobler vocation” than ending up in pieces of meat, he says.
