A 66-year-old US resident, Tim Andrews, has successfully undergone a human kidney transplant after living for a record nine months with a genetically modified pig kidney. This was reported by The New York Times.

Andrews suffered from kidney failure resulting from hypertension and diabetes mellitus. His rare blood type significantly reduced the chances of finding a compatible human donor. For this reason, in January 2025, he agreed to an experimental surgery involving the transplantation of a kidney harvested from a genetically modified pig.

The pig kidney continued to function in the patient's body for 271 days. During this period, the organ performed the function of blood purification, allowing Andrews to discontinue dialysis treatment. The patient's appetite improved and his muscle mass recovered.

Later, due to the formation of blood clots in the blood vessels, the transplanted organ had to be removed. Nevertheless, this experiment provided crucial data for exploring the possibilities of xenotransplantation, which is the transplantation of animal organs into humans.

In January 2026, Andrews received a kidney from a compatible human donor. According to doctors, this case demonstrated that the prior transplantation of genetically modified animal organs does not pose an obstacle to a subsequent human kidney transplant.

The surgery was performed under a program by the US Food and Drug Administration (FDA). As part of this program, genetically modified pig kidneys prepared by the biotechnology company eGenesis were transplanted into five patients. Three of them lived with such organs for more than eight months.

Experts are exploring the use of genetically modified animal organs as a temporary "bridge" for patients awaiting a human donor. Tim Andrews' case is valued as one of the important clinical experiments for the future development of xenotransplantation technologies.