Tim Andrews, who had end-stage kidney disease, was 66 when he received the pig kidney in January 2025
I would like to be emailed about offers, events and updates from The Independent. Read our Privacy notice
In a world first, a man has lived without dialysis for nine months after receiving a genetically modified pig kidney.
Tim Andrews, 66, from New Hampshire, suffered end-stage kidney failure brought on by type 2 diabetes before undergoing the pioneer procedure in the US in January 2025.
Doctors explained that the animal organ, taken from a Yucatan miniature pig and genetically engineered for compatibility with the human immune system, served as a temporary "bridge" while Mr Andrews awaited a transplant from a human donor.
He lived successfully with the genetically edited organ for 271 days before transitioning to a short period of dialysis and subsequently receiving a donor human kidney.
Medical teams said the milestone marks the longest recorded dialysis-free survival following a pig kidney transplant in a living patient, and the first successful transition from pig-to-human kidney transplantation.
It was transplanted in January last year and began working immediately.
After roughly six months, damage developed in the kidney’s blood vessels which progressed to organ failure and the pig kidney was removed.
Mr Andrews later received a kidney from a dead human donor.
In a CNN documentary, he said the pig kidney transplant was a “miracle”, adding: “I was alive, and I hadn’t been in a long time.”
He said he was able to cook, vacuum and take long walks with his dog Cupcake.
Researchers said no pig viruses or other pig pathogens were detected at any point.
They added that the findings support pig kidney transplantation as potentially a bridge for people facing long waits for a human kidney, while highlighting the need for further research.
The team, from Mass General Brigham academic centres and hospitals in the US, published their findings in the Lancet medical journal.
