Tim Andrews, a 67-year-old from New Hampshire, has become the first person globally to survive a genetically modified pig kidney transplant, living with the organ for 271 days before a human kidney became available. His experience, published in The Lancet, suggests xenotransplantation could serve as a vital bridge for patients awaiting human organ donations.
Andrews sought the experimental procedure, known as xenotransplantation, after enduring two years of kidney failure exacerbated by diabetes. The condition necessitated three-day-a-week dialysis, a treatment that left him fatigued and with muscle wasting, significantly impacting his mobility. Following a heart attack during his treatment, Andrews became convinced he needed an alternative.
His search led him to the case of Richard Slayman, a 62-year-old who received a similar pig kidney transplant in 2024. Although Slayman's transplant was initially successful, he died two months later due to an unrelated heart issue, with no indication that the transplant was a factor.
Inspired by Slayman's case, Andrews approached the team at Massachusetts General Hospital, who had performed Slayman's surgery. After undergoing physical therapy to improve his strength and reduce the risk of organ rejection, Andrews underwent the three-hour procedure in January 2025. His diseased kidneys were removed, and he received a genetically modified kidney from a Yucatan miniature pig, which he named Wilma.
Initially, Andrews reported feeling strong, attributing it to steroid medication. However, as these were tapered off, he experienced a gradual decline. Reduced urination and flu-like symptoms indicated organ rejection. After 271 days, the pig kidney was surgically removed.
Left without functioning kidneys, Andrews returned to dialysis, joining the approximately 90,000 Americans on the waiting list for a human kidney transplant. The scarcity of human organs is a global issue, with over 7,200 people in Britain, including 138 children, also awaiting transplants, while only about 3,000 kidney transplants are performed annually in the UK.
Andrews described the return to dialysis as a return to a state of constant fatigue and illness. He believed he had only months to live. However, in January 2026, he received a call for a near-perfect human kidney match.
The human kidney was implanted, and Andrews was discharged within days. He continues to manage his health, now taking 20 anti-rejection medications, down from the initial 51, and monitoring his blood sugar levels due to potential side effects of immunosuppressants. He expressed gratitude for the donated human organ, sending a message to the donor's family stating their relative was a hero whose donation saved his life and offered hope to millions.
Andrews hopes that xenotransplantation will become more common, providing a viable alternative for those facing long waits. He encourages others to consider organ donation, emphasizing the profound impact it has on recipients. "People should be donors," he stated. "There's no reason not to have your driver's license say 'donor' on it."