Pig kidney becomes first-ever bridge to the real thing

A New Hampshire man was recently on the receiving end of perhaps the world’s strangest bridge loan: a genetically modified pig kidney that successfully kept him off dialysis long enough to receive a human kidney transplant.

The milestone marks the first successful transition from a pig kidney transplant to a human kidney transplant.

That’ll do, pig

Tim Andrews, a 66-year-old with end-stage kidney disease, received the pig kidney at Massachusetts General Hospital in January 2025.

• The kidney came from a genetically edited pig designed to make its organ more compatible with humans and reduce risks from pig viruses.
• It worked inside Andrews’ body for 271 days (~9 months) without him needing dialysis, the longest such survival on record.

But after Andrews’ immunosuppressive medication was reduced because of an infection, the kidney eventually developed inflammation and damage leading to organ failure.

Andrews returned briefly to dialysis before receiving a human donor kidney in January 2026. That organ began working immediately, with doctors finding no evidence the pig transplant made his immune system more likely to reject the human organ.

Why it’s a big deal: An average of ~11 Americans die every day while waiting for an organ transplant. And of the ~110,000 people on the national organ transplant waiting list, some 85% are in need of a kidney.

Looking ahead…Altogether, five patients at Mass General Brigham have received modified pig kidneys from biotech company eGenesis, with three already living with the organs for 8+ months. eGenesis is also starting a formal clinical trial next year with 33 patients receiving pig kidneys, while other researchers are currently experimenting with transplanting modified pig hearts into human patients.