Adam Griesemer, MD, delivers the genetically engineered pig kidney operating room at NYU Langone Health.[ Joe Carrotta for NYU Langone Health]

NYU Langone surgeons have transplanted a genetically engineered pig kidney that continues to function well after 32 days in a brain dead man. This represents the longest period that a such a xenotransplant has functioned in a person. The procedure was performed on July 14, 2023 and the study will continue through mid-September 2023.

“This work demonstrates a pig kidney—with only one genetic modification and without experimental medications or devices—can replace the function of a human kidney for at least 32 days without being rejected,” said one of the surgeons, Robert Montgomery, MD, DPhil, and director of the NYU Langone Transplant Institute.

Montgomery previously performed the world’s first genetically modified pig kidney transplant into a human decedent in 2021, followed by a second similar procedure soon after. The results of these two kidney transplants were described in a 2022 NEJM article. Surgeons with the Transplant Institute also performed two genetically engineered pig heart transplants in summer 2022. So, this was the fifth xenotransplant performed at NYU Langone.

The procedure was possible because a 57-year-old male organ donor’s family donated his whole body after he was declared brain dead and it was determined his organs or tissues were not suitable for transplant.

The first hurdle in xenotransplants is preventing hyperacute rejection, which typically occurs just minutes after an animal organ is connected to the human circulatory system.

The alpha-gal gene has been identified as responsible for a rapid antibody-mediated rejection of pig organs by humans. To address this, pigs have been bred with a knockout of the alpha-1,3-galactosyltransferase gene and with subcapsular autologous thymic tissue. The kidney and thymus gland used in this procedure came from a GalSafe pig, an animal engineered by Revivicor.

In this case, to ensure the body’s kidney function was sustained solely by the pig kidney, both of the transplant recipient’s native kidneys were surgically removed. One pig kidney was then transplanted and started producing urine immediately without any signs of hyperacute rejection. During the observation phase, intensive care clinical staff maintained the decedent on support while the pig kidney’s performance was monitored and sampled with weekly biopsies.

In the United States, more than 103,000 people are on the waiting list for a transplant, with nearly 88,000 of those waiting for a kidney, according to recent federal Organ Procurement and Transplantation Network (OPTN) data. In 2022, about 26,000 people received a kidney transplant. Meanwhile, nearly 808,000 people in the U.S. have end-stage renal disease.

“There are simply not enough organs available for everyone who needs one,” said Montgomery, who received a hepatitis C–positive heart transplant himself in 2018. “Too many people are dying because of the lack of available organs, and I strongly believe xenotransplantation is a viable way to change that.”

“We think using a pig already deemed safe by the FDA in combination with what we have found in our xenotransplantation research so far, gets us closer to the clinical trial phase,” said Montgomery. “We know this has the potential to save thousands of lives, but we want to ensure the utmost safety and care as we move forward.”

Also of Interest