Record Survival After Pig Kidney Transplant Marks Major Milestone

A 67-year-old man named Tim Andrews from New Hampshire has set a new record by living 271 days with a gene-edited pig kidney before it was removed, doctors say. The transplant occurred on January 25, 2025, at Massachusetts General Hospital. 

Andrews had been on dialysis for more than two years because of end-stage kidney disease and faced a long wait for a human donor kidney due to his rare blood type. 

The kidney came from a pig whose genes were extensively edited using CRISPR to remove pig-specific proteins and add human genes to reduce rejection risk. 

Doctors say while the kidney eventually declined and was removed on October 23, the long survival period is a major step forward in the field of xenotransplantation (animal to human organ transplants). 

More than 100,000 people in the U.S. alone wait for kidney transplants, and many die before receiving a donation. Scientists hope pig kidneys may help fill this gap. 

Researchers now plan further trials to evaluate how long pig organs can safely function in humans and how immunosuppressive regimens need to be adjusted.