Dr Ayares cradles a genetically-modified piglet at the research farm, noting that these piglets are very high-value animals as millions of US dollars has gone into the research to make their kidneys suitable for humans. — AFP
On a farm in the southern American state of Virginia, Dr David Ayares and his research teams are breeding genetically-modified pigs to transplant their organs into human patients.
Revivicor, the biotech company Dr Ayares leads, is at the forefront of xenotransplantation research – the implantation of animal organs into humans – which aims to solve a chronic organ shortage that has thousands of Americans dying each year.
It was on this farm that the company bred a pig whose kidney was recently transplanted into kidney failure patient Towana Looney, according to an announcement made on Dec 17 (2024) by a New York hospital.
“It’s just an exciting time,” Dr Ayares said, during a recent tour of the research farm.
The pigs are genetically modified to make their organs less likely to be rejected by patients’ immune systems.
“These pigs are not typical farm pigs,” he said as he cradled several pink piglets in his arms.
“Millions of dollars have gone into the production of these genetics, and so they’re very high-value animals.”
For more than 20 years, Revivicor in Blacksburg, Virginia, has been conducting research to turn pig-to-human transplantation from science fiction to life-saving medical care.
In the United States alone, more than 100,000 people are on the transplant list and thousands die every year waiting – most often for a kidney – according to health authorities.
Gradual progress
Since 2021, several American surgeons have successfully transplanted genetically-modified pig kidneys and hearts into humans, most of them supplied by Revivicor.
Another key provider is the biotech firm eGenesis.
The first trials were carried out on brain-dead people, before the procedure was attempted on a handful of seriously ill patients.
While those patients died within weeks of the operation, the animal organs they received were not immediately rejected by their immune systems, which scientists hailed as a promising sign.
In a dark laboratory several kilometres away from the research farm, Revivicor Cell Biology and Nuclear Transfer head Todd Vaught has his eyes glued to a microscope.
With a pipette, he pierces a pig egg (ovum) to remove its DNA (deoxyribonucleic acid) and replace it with cells that have “all the instructions needed to make a genetically-modified pig”.
A few hours later, the edited eggs are implanted into sows.
Four months later, new litters are born.
While xenotransplantation research is happening in various parts of the world, the US is a clear leader in the field.
French sociologist Catherine Rene criticised what she characterises as mistreatment of the pigs as merely vessels for organs destined for humans.
“Ultimately, there is very little room for recognition of the donor animal, of the gift that is made,” she said.
Dr Ayares disagreed.
“Hundreds of millions of pigs are used every year as food,” he said.
“I would argue that this is a much higher calling for that pig organ to be used for transplantation.”
Million dollar price tag
The first line of pigs developed by Revivicor carried only one genome edit meant to deactivate the animal’s production of a substance that causes humans to reject the transplanted organ.
The second has 10 modified genes, six of which come from human DNA in order to improve biological compatibility.
It is with this second line of pigs that United Therapeutics (UT), Revivicor’s parent company, is thinking big.
In March, the publicly-traded company opened another medical facility near Blacksburg where, in a brand-new operating room, pigs’ kidneys will be removed and prepared for transfer to the receiving patient.
The rest of the pig will be discarded.
Spokesman Dewey Steadman said the facility has “rigorous controls” in place to prevent any infection of the 200 animals being kept there.
The company’s goal is to begin several years of clinical studies on patients in 2025, and if the US Food and Drug Administration (FDA) gives the green light, to begin full-scale production of genetically-modified pigs in 2029.
UT is already planning to invest billions of US dollars into building more and bigger facilities.
The company is considering selling kidneys for around US$1 million (about RM4.5 million) each, which is close to the cost of 10 years of dialysis for patients in the US, according to Steadman.
Making pig kidneys available to a large number of patients will not be an easy task in the US, which lacks universal health care.
But Dr Ayares hopes that with health insurance, “the patient is not bearing a million dollars ... price tag”. – AFP Relaxnews
