News release

From: The Lancet

The Lancet: Genetically modified pig kidney kept a man off dialysis for nine months before a successful human kidney transplant, in world-first report

A genetically modified pig kidney kept a 66-year-old man with kidney failure free of dialysis for a record nine months, according to the first report of its kind published in The Lancet. This is also the first time a pig kidney has been used as a temporary “bridge” to a human transplant. 

Kidney transplantation provides the best survival and quality of life for patients with end-stage kidney disease, but organ demand far exceeds supply. Transplanting genetically engineered pig organs has been proposed as a solution to the organ shortage, however the first pig kidney transplant into a living person, in 2024, ended after 52 days when the patient died from unrelated heart problems [1] and no previous studies have documented xenograft survival beyond two months.

In this new case study, the patient had kidney failure caused by type 2 diabetes. He had an estimated 9% chance of receiving a human kidney within five years, against a more than 40% risk of dying or being removed from the waiting list.

The kidney came from a Yucatan miniature pig and was genetically engineered to be compatible with the human immune system. It was transplanted in January 2025 and began working immediately. After roughly six months, damage developed in the kidney’s blood vessels which progressed to organ failure and the kidney was removed approximately nine months after transplantation. The patient did not produce any detectable antibodies against the pig kidney, suggesting a different mechanism to that usually seen in organ transplant rejection.

After several months back on dialysis, the patient received a kidney from a deceased human donor, which worked well during the six months of follow-up. There were no new antibodies against human tissue detected, indicating the pig kidney had not made it harder for the human kidney transplant to work successfully. No pig viruses or other pig pathogens were detected at any point.

The authors caution that this is a single patient with no comparison group, and that the outcome reflects careful patient selection and intensive specialist care that may not be available elsewhere. They say the findings support pig kidney transplantation as a potentially bridge for people facing long waits for a human kidney, while highlighting the need for further research.