A pig kidney transplanted into a human patient has surpassed previous records, lasting for nearly nine months and allowing the recipient to live without dialysis. The case marks the first time a pig organ has been used as a bridge to a human donor transplant.
A record-setting transplant
Tim Andrews, a 66-year-old from New Hampshire, received the genetically modified organ under an expanded access program last year. He was suffering from end-stage kidney disease caused by type 2 diabetes and had only a small chance of receiving a human organ within five years.
The transplant was performed at Massachusetts General Hospital in Boston. The kidney functioned for 271 days, a new record for xenotransplantation, before failing and prompting the patient to receive a human donor organ.
Just two years after the world’s first pig-to-human kidney transplant, which ended after 52 days, this procedure demonstrates that the technology is improving quickly. The milestones in cross-species transplantation rely on cutting-edge biotechnologies, including the use of CRISPR gene editing to remove harmful pig genes and add certain human genes to improve the organ’s compatibility with recipients.
Expanding the treatment pool
Since March 2024, five patients with kidney failure have received the EGEN-2784 kidney. Three have achieved sustained function for at least eight months without dialysis. Two patients have already successfully transitioned to human donor kidneys, officials said.
The FDA has cleared a phase 1/2/3 trial called RESTORE. That study will test the EGEN-2784 kidney in 33 patients aged 50 to 70 who are on the waiting list. eGenesis expects to begin that trial in the first quarter of next year.
For patients stuck on long waiting lists, this technology offers a chance to bypass the bottleneck of organ availability. When a human organ finally becomes available, the pig kidney has already kept the patient alive and potentially bought enough time to avoid complications associated with prolonged dialysis. This practical benefit of bridging the gap between failure and success is what makes the approach clinically significant.
Addressing the shortage
“The organ shortage is the greatest crisis we have right now in transplantation,” said Leonardo Riella of the Centre for Transplantation Sciences at Mass General Brigham. “We know that the best treatment option for patients with end-stage kidney disease who have developed renal failure is transplantation, but we simply don’t have enough human organs to transplant in a timely manner.”
In the US, around 100,000 people are waiting for a kidney, but only about 25,000 transplants occur each year. The study authors note that this transplant served as a bridge, allowing the patient to become dialysis-free during the wait.
“Our vision is that xenotransplantation could help address this gap, initially as a bridge to get patients off dialysis while they wait for a human donor kidney and, potentially, as we establish long-term safety and durability, as a destination therapy in its own right,” Riella added.
