Pig kidney transplant successfully completed at Massachusetts hospital
For the second time in less than a year, doctors at Massachusetts General Hospital have transplanted a genetically-edited pig kidney into a living person.
The hospital, which completed the world's first kidney xenotransplantation in March 2024, said the latest transplant was completed during a 2.5-hour procedure on Jan. 25.
With the procedure, Tim Andrews, 66, of Concord, New Hampshire, became the fourth person in the world to receive a genetically-edited pig kidney. He is only the second person known to be living with a pig kidney.
He was discharged from the hospital on Feb. 1, with his new kidney functioning as expected.
“As soon as I woke up after the surgery, the cloud of dialysis disappeared. I felt re-energized and revitalized. It was a miracle," Andrews said in a statement provided by the hospital.
Prior to the transplant, Andrews suffered from end-stage kidney disease and required two years of daily dialysis, the hospital said. He suffered a heart attack in July 2023 and faced a long wait time for a human organ because of his O-group blood type.
"While most patients wait 3 to 5 years for a kidney, those with O-positive or O-negative blood types often wait 5 to 10 years, making their chances of receiving a donor organ even more difficult," the hospital said.
The genetically-edited pig kidney was provided by eGenesis of Cambridge, which used CRISPR-Cas9 technology to remove harmful pig genes and add certain human genes to improve its compatibility. The hospital said that the team also inactivated porcine endogenous retroviruses in the pig donor to eliminate any risk of infection.
“This second xenotransplant provides us with another excellent opportunity to learn how we can make genetically-edited pig organs a viable, long-term solution for patients. Although we have a long way to go to make that a reality, this transplant is an important next step that has given us optimism to achieve that goal,” lead surgeon Tatsuo Kawai said in a statement.
"The magnitude of what these doctors and nurses accomplished is unbelievable and I want to thank them for giving me a new lease on life," Andrews said. "But this transplant isn’t about me. It’s about all the people who I met at the dialysis clinic, and I saw what they were going through. There are more than 500,000 people on dialysis, and I want to inspire them to never give up hope because that’s what this transplant provides. It’s a glimmer of hope."
Richard Slayman, 62, of Weymouth, was the recipient of the world’s first successful transplant of a genetically-edited pig kidney. He died less than two months after the historic transplant.
Video below: First xenotransplant discussed
Doctors said Slayman's kidney continued functioning up to the time of his death.
New research on the procedure was also . It reveals that Slayman died from "unexpected, sudden cardiac causes" 52 days after his transplant and that an autopsy found no evident rejection of the kidney.
According to the United Network for Organ Sharing, more than 100,000 people in the U.S. await an organ for transplant and 17 people die each day waiting for an organ.
The xenotransplant surgeries are performed under the FDA's Expanded Access Protocol, which is commonly known as compassionate use. The FDA approved Andrews' transplant in December.
Massachusetts General Hospital officials said they plan to perform two additional xenotransplants this year.
Video below: Reflecting on Slayman's transplant
