The Cocktail Report (sound really smart around your friends):
Tim Andrews, 66, lived 271 days without dialysis on a pig kidney carrying 69 genetic edits, then received a human kidney in January 2026.
He is the first person ever bridged from a pig organ to a human transplant, and eGenesis reports a second patient has since done the same.
A national analysis of 54,669 kidney transplant candidates over 60 projected that almost half would die before a deceased-donor kidney arrived.
The pig kidney began failing after about six months, once his anti-rejection drugs were lowered to fight an infection.
Two FDA-cleared trials, EXPAND and RESTORE, are testing pig kidneys in patients between 50 and 70.
If you or someone you love has diabetes or high blood pressure, kidney failure is a real risk later in life. The hard part is what comes next: the wait for a donor kidney often outlasts the patient.
More than 90,000 Americans are waiting for a kidney, and about 12 of them die every day still waiting. A 2009 analysis of 54,669 candidates over age 60 projected that 46 percent would die before receiving a deceased-donor transplant, rising to 61 percent among those with diabetes.
That is where xenotransplantation comes in, the use of organs from another species. Tim Andrews, a man with kidney failure from type 2 diabetes, became its most important test case so far.
On January 25, 2025, surgeons at Massachusetts General Hospital gave Andrews, then 66, a kidney from a genetically engineered Yucatan miniature pig. He had been told the wait for a human kidney could be seven years.
The kidney came from eGenesis, a company co-founded by Harvard geneticist George Church. Its pigs carry 69 genetic edits: three pig sugar molecules removed to prevent instant rejection, seven human genes added to calm inflammation and clotting, and 59 copies of dormant pig viruses (endogenous retroviruses) switched off.
That design was tested first in monkeys. In a 2023 Nature study, kidneys with the full set of edits survived a median 176 days versus 24 days for kidneys with only the sugar edits, and one monkey lived 758 days.
In Andrews, the kidney worked immediately. An early bout of rejection responded to treatment, no pig infection passed to him, and he stayed off dialysis (machine filtering of the blood) for 271 days.
After about six months, doctors lowered his immunosuppressants, the drugs that keep the body from attacking a transplant, because he had developed an infection. The pig kidney then developed damage to its tiny blood vessels, called microvascular injury, along with inflammation, and the organ gradually failed.
Surgeons removed it in October 2025. After 82 days back on dialysis, Andrews received a human kidney in January 2026, and it worked immediately with no sign that the pig organ had primed his immune system against it.
His case, described by the Mass General Brigham team in the Lancet, is the longest dialysis-free stretch on a pig kidney in a living person. It is also the first time a pig organ bridged a patient to a human one.
To be clear about what one case can prove, the published record is a single patient, and the reason for the late blood-vessel damage is not fully understood.
eGenesis reports five patients have now received its kidneys, with three passing eight months off dialysis and a second moving on to a human kidney. Those figures come from a company release, not a peer-reviewed paper, and the study was funded by the hospital and eGenesis, with company employees among its authors.
The next step is controlled testing. United Therapeutics began its EXPAND trial in November 2025 for patients 55 to 70, and the FDA has cleared eGenesis's 33-patient RESTORE trial for patients 50 to 70, set to start in early 2027.
Notice those age ranges. This is a therapy being designed for older adults, the group most likely to run out of time on a waiting list.
For you, the practical step is unchanged: protect your kidneys now by controlling blood sugar and blood pressure. If a family member is on a transplant list, it is worth asking the transplant center whether they could qualify for one of these trials.
Why Should You Care?
A shortage of donor organs quietly shortens the lives of older adults with kidney failure. Pig kidneys will not fix that yet, but they have now shown they can buy the time needed to reach a human transplant.
1. Mass General Brigham. How a pig-kidney xenotransplant served as a successful bridge to human transplant for patient with end-stage kidney disease. September 2026 news release describing Riella L, Kawai T, et al., The Lancet, DOI 10.1016/S0140-6736(26)01295-X. https://news.massgeneralbrigham.org/en/pig-kidney-xenotransplant-bridge-to-human-transplant
2. Harvard Medical School. Patient who received pig kidney becomes first to progress to human kidney transplant. September 3, 2026. https://hms.harvard.edu/news/patient-who-received-pig-kidney-becomes-first-progress-human-kidney-transplant
3. Gallagher J. Transplanted pig kidney works in US man's body for record 271 days. BBC News, September 3, 2026. https://www.bbc.com/news/articles/c305qn2jeggo
4. Anand RP, Layer JV, Heja D, et al. Design and testing of a humanized porcine donor for xenotransplantation. Nature. 2023;622:393-401. DOI 10.1038/s41586-023-06594-4. PMID 37821590. https://pmc.ncbi.nlm.nih.gov/articles/PMC10567564/
5. Schold J, Srinivas TR, Sehgal AR, Meier-Kriesche HU. Half of kidney transplant candidates who are older than 60 years now placed on the waiting list will die before receiving a deceased-donor transplant. Clinical Journal of the American Society of Nephrology. 2009;4:1239-1245. PMID 19541814. https://pmc.ncbi.nlm.nih.gov/articles/PMC2709520/
6. Woolley BE. Kidney xenotransplantation enters the clinical trial era. Artificial Organs. 2026;50(9):1205-1206. DOI 10.1111/aor.70217. https://pmc.ncbi.nlm.nih.gov/articles/PMC13525214/
7. eGenesis. eGenesis announces clinical update in ongoing Expanded Access study of EGEN-2784 in patients with kidney failure. Business Wire, September 3, 2026. https://www.businesswire.com/news/home/20260903759233/en/
