Pig kidney keeps patient off dialysis for 271 days before human transplant
A genetically modified pig kidney supported a 66-year-old patient for 271 days without dialysis before he received a human kidney, offering early evidence that xenotransplants could serve as a bridge while patients await donor organs.
A genetically modified pig kidney functioned inside a patient with
end-stage kidney disease for 271 days, keeping him off dialysis until he
received a human kidney transplant, according to a paper published
Thursday in The Lancet.
The case offers promise for how
xenotransplantation — cross-species transplantation involving cells,
tissues or organs — can potentially be used as a temporary ‘bridge’ for
those waiting for human donors.
The paper, titled Porcine kidney
xenotransplantation as a bridge to allotransplantation: a first-in-human
study, reports outcomes from a porcine kidney xenograft in a living
recipient followed by human allotransplantation — the surgical transfer
of cells, tissues or organs from one individual to another of the same
species but who is genetically different.
Pig kidney keeps patient off dialysis for 271 days
The
authors mention that 66-year-old Time Andrews received the genetically
edited pig kidney in January 2025, and his case represents the longest
dialysis-free survival following porcine kidney xenotransplantation in a
living human and the first transition to human kidney transplantation.
The pig kidney had undergone several gene edits to prevent rejection by
the human body.
“This case provides the first clinical evidence
that a genetically engineered pig kidney can serve as a bridge to a
human kidney transplant, allowing patients to avoid prolonged dialysis
while preserving future transplant options,” lead author Leonardo V.
Riella told CNBC-TV18 over email.
“Challenges remain, including
improving long-term durability, preventing late microvascular injury,
and simplifying immunosuppression, but each clinical experience is
helping us move closer to making xenotransplantation a safe and broadly
available treatment,” Riella said.
Mike Curtis, president and chief executive of eGenesis, the biotechnology company that produces the genetically
modified pigs used for xenotransplantation, told CNBC-TV18 that the case
provided important clinical evidence that a genetically engineered pig
kidney could sustain kidney function while a patient awaited a human
donor organ.
“In this case, the porcine kidney supported the
patient for more than nine months, and he later received a human donor
kidney that demonstrated immediate function. Importantly, there was no
evidence of clinically significant sensitization that would have
prevented the subsequent human transplant,” Curtis said.
A potential bridge to human kidney transplants
The
world’s first porcine kidney xenotransplant to a living human recipient
occurred in 2024 at Massachusetts General Hospital, with the patient
surviving 52 days before dying from cardiac causes unrelated to the
transplant. No previous studies have documented xenograft survival
beyond two months, a successful “bridge” to receipt of a human organ, or
the mechanisms leading to late xenograft failure in living recipients,
according to a release from Mass General Brigham, where the genetically
modified pigs were used.
The authors mention that the case shows
that porcine kidney xenotransplantation can provide prolonged renal
support. Kidney xenotransplantation has the potential to provide
prolonged dialysis-free support while also serving as a bridge to
subsequent human allotransplantation.
“Kidney xenotransplantation
offers a potential solution to the organ shortage, but questions remain
regarding durability, zoonotic infection risk, and whether the
immunological response to the xenograft elicits sensitisation that could
complicate subsequent allotransplantation,” the authors write.
Challenges remain before wider use
Advancements
in genetic engineering and extensive research into developing
anti-rejection drugs have accelerated progress in xenotransplantation in
recent years.
While this is an important step for
xenotransplantation, larger clinical studies will be needed to establish
whether genetically modified pig kidneys can become a safe and reliable
bridge for patients waiting for human organs. There is also a need for
greater collaboration and further scientific studies. Another challenge
relates to ethical concerns, with many animal-support groups strongly
opposed to genetically modifying animals.