From Pig to Human: A New Bridge in Kidney Transplantation

Lab-Grown Food

Imagine a pig kidney keeping a patient alive for almost nine months before a human kidney takes over—this breakthrough could change transplant waiting lists forever.

TL;DR
• First human case of pig kidney bridging to human transplant, lasting 271 days without dialysis.
• Study shows promise and highlights microvascular injury as a key challenge.
• Findings support xenotransplantation as a viable bridge to address organ shortages.

Summary
Tim Andrews, a 66‑year‑old with end‑stage kidney disease, received a genetically edited pig kidney in January 2025 and survived 271 dialysis‑free days before transitioning to a donated human kidney in January 2026. The case marks the longest xenograft survival reported and the first successful bridge to human transplantation, highlighting a potential pathway to alleviate the organ shortage crisis.
• Monitor xenograft function continuously for early rejection signals.
• Reduce immunosuppression cautiously after infection control.
• Incorporate donor genetic modifications to mitigate microvascular injury.
• Design flexible clinical protocols that allow seamless transition to human organs.
• Invest in scalable xenotransplant platforms to expand patient access.

The Lancet paper authored by Harvard Medical School surgeons Leonardo Riella and Tatsuo Kawai details the clinical course, noting immediate kidney function, a resolved T‑cell‑mediated rejection episode, and no detected pig pathogen transmission. After six months, reduced immunosuppression coincided with microvascular injury, prompting organ failure and subsequent human kidney transplantation with immediate graft function and no sensitization.

The study builds on earlier work, including the 2024 world‑first pig‑to‑human kidney transplant at Mass General, which survived 52 days. Collaboration with eGenesis, co‑founded by geneticist George Church, provided the edited organs and contributed extensive preclinical data published in Nature (2023). Funding from Mass General, eGenesis, and pharmaceutical partners supported the expanded‑access FDA application and operational logistics.

Findings underscore both promise and areas for improvement: microvascular injury informs future immunosuppressive regimens, donor genome editing, and monitoring strategies. The successful bridge demonstrates that xenotransplantation can extend dialysis‑free intervals, offering patients critical time while awaiting scarce human kidneys. Continued refinement of genetic edits, scalable production, and adaptive clinical frameworks will be essential to transition xenografts from bridge therapy to potential long‑term solutions.

Will xenotransplantation become the standard bridge to human kidneys, reshaping transplant timelines and patient outcomes?