The experiment is one of several aimed at speeding the start of clinical trials on living humans.
A genetically modified pig kidney transplanted into a brain-dead patient over a month ago is still working normally, researchers have found.
The procedure was carried out by a team of surgeons in New York on 14 July, and researchers are now tracking the kidney’s performance for a second month.
It is the longest period a gene-edited pig kidney has functioned in a human.
“Is this organ really going to work like a human organ? So far it’s looking like it is,” said Dr Robert Montgomery, director of NYU Langone’s transplant institute.
The deceased patient, Maurice “Mo” Miller from upstate New York, died suddenly at 57 with a previously undiagnosed brain cancer – ruling out routine organ donation.
The possibility that pig kidneys might one day help ease a dire shortage of transplantable organs is what persuaded his family to donate his body for the research.
Dr Montgomery replaced the deceased patient’s own kidneys with a single kidney from a genetically modified pig – and watched it immediately start producing urine.
The NYU research is one of several aimed at speeding the start of clinical trials on living humans.
Also on Wednesday, researchers at the University of Alabama at Birmingham (UAB) reported a pair of genetically modified pig kidneys had worked normally inside another donated body.
The kidneys were not rejected and made urine within four minutes, producing more than 37 litres in the first 24 hours.
They continued to function as they would in a living human for the entirety of the seven-day study.
The UAB findings have been peer reviewed and published in the Jama Surgery journal.
The unnamed recipient of the pig kidneys was a 52-year-old man who had high blood pressure and stage two chronic kidney disease – and wanted his body donated for research.
Jayme Locke, director of UAB’s Heersink School of Medicine and lead author of the paper, said: “It has been truly extraordinary to see the first-ever pre-clinical demonstration that appropriately modified pig kidneys can provide normal, life-sustaining kidney function in a human safely and be achieved using a standard immunosuppression regimen.”
She added: “We were able to gather additional safety and scientific information critical to our efforts to seek FDA (Food and Drug Administration) clearance of a Phase I clinical trial in living humans and hopefully add a new, desperately needed solution to address an organ shortage crisis responsible for tens of thousands of preventable deaths each year.”
Kidneys were first transplanted from a genetically modified pig to a human in January 2022 – also carried out by researchers at UAB.
Jim Parsons, the 57-year-old transplant recipient, was brain dead. The organ donor’s family allowed him to be kept on a ventilator to keep his body functioning during the study.
The latest study was conducted using the Parsons Model, developed at UAB to evaluate the safety and feasibility of pig-to-human kidney transplants, without risk to a living human.
