Transplanted Pig Kidney Still Working After a Record-Setting 9 Months in a Patient
A patient at Massachusetts General Hospital has lived with a genetically modified pig kidney for 285 days without needing dialysis, setting a new record for the longest a human has survived with a transplanted pig organ. The milestone, reported by biotech firm eGenesis, underscores growing evidence that gene-edited pig kidneys could ease the severe shortage of human donor organs and reduce the physical toll of long-term dialysis while patients wait for a transplant.
The woman received her transplant on 22 November last year and is the fifth person to receive an eGenesis kidney under the US Food and Drug Administration's expanded access pathway for experimental treatments. The previous record of 271 days was set by Tim Andrews, whose pig kidney was later removed after his kidney function declined; he has since received a human transplant, as has a second patient who carried a pig kidney for eight months. A Lancet paper published alongside the announcement found Andrews' organ failed due to small blood clots, insight eGenesis says is shaping adjustments to immunosuppressant regimes. More than 95,000 people are on the US kidney waiting list, yet fewer than 28,000 transplants were carried out in 2025; the FDA has approved a formal trial of up to 33 patients from 2027, with further individual transplants planned before then.
In short
- Pig kidney functions in patient for 285 days, a new record
- eGenesis used Crispr gene editing to adapt the organ for humans
- Aims to ease severe US shortage of donor kidneys; formal trial set for 2027
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The strongest fair case each way — we don't pick a winner.
The case for
Pig kidney transplants could offer a new source of organs for people facing long waits, reducing time on dialysis and potentially saving lives. The patient’s 285 days without dialysis, alongside lessons from earlier cases, provides encouraging evidence that the approach may become more reliable as researchers refine treatment and study outcomes.
The case against
The record is a milestone in a very small number of experimental cases, and earlier pig kidneys have failed, including through blood clots. Wider use should therefore depend on careful trials that establish safety, durability and likely benefits, given the serious risks of transplantation and the uncertainty about how well these organs will work over time.
Explained simply
Kidneys filter waste and excess fluid from the blood. When they fail, people may need regular dialysis, which does some of this work, or a kidney transplant from a human donor. Many people in the United States are waiting for a donor kidney, and far fewer transplants are carried out each year than there are people on the waiting list.
Researchers are testing whether kidneys from pigs can help address this shortage. The organs are genetically modified to make them more suitable for people, but the body can still reject them or develop other problems. Patients receiving them are part of experimental treatment programmes, including one run by biotech company eGenesis at Massachusetts General Hospital.
Earlier recipients have later received human kidneys after their pig organs stopped working or were removed. Research into one such case found small blood clots in the pig kidney, and the company says this is informing changes to the medicines used to prevent rejection. The US regulator has approved a trial of up to 33 patients, which is planned to begin in 2027.