The First Pig-to-Human Kidney Transplant Patient Is Thriving at One Year

365 Days and Counting

Rick Slayman received a genetically modified pig kidney in March 2025 at Massachusetts General Hospital. One year later, the kidney functions normally, showing no signs of rejection. Slayman, who previously required dialysis three times weekly, now lives without it. His creatinine levels — the key indicator of kidney function — are within normal range.

This milestone matters enormously. Previous pig organ transplants in humans lasted weeks to months before rejection. Slayman's year-long success suggests that the genetic modifications — 69 edits to the pig genome, removing pig viruses and adding human-compatible proteins — have solved the acute rejection problem.

The Organ Shortage Context

Over 100,000 Americans are waiting for organ transplants. 17 people die every day waiting. The demand far exceeds the supply of human donor organs and always will. Xenotransplantation — using animal organs — is the only plausible path to eliminating the waitlist.

eGenesis, the company that engineered Slayman's pig kidney, is now conducting trials with 12 additional patients. If those results match Slayman's, the FDA could approve pig kidney transplants for general use by 2028.

Ethical Considerations

Animal welfare groups have raised concerns about breeding pigs for organ harvesting. The modified pigs live in sterile facilities and are euthanized during organ retrieval. Proponents argue that this is ethically comparable to raising animals for food — but with the benefit of saving human lives directly.