A Third Person Has Received a Transplant of a Genetically Engineered Pig Kidney

Slayman is the first pig kidney recipient to qualify for a human kidney, but due to his rare blood type, he may have to wait six to seven years to get one. Pisano and the two pig heart disease patients were ineligible for human organs due to other medical issues.

Looney ran out of options. Her health was deteriorating, and after years of searching, the chances of finding a matching human kidney were slim. Her doctor, Jayme Locke, then an abdominal transplant surgeon at the University of Alabama at Birmingham, had previously performed short-term pig kidney transplants on brain-dead recipients and recommended the experimental procedure as a last resort. Looney’s transplant was approved by the U.S. Food and Drug Administration’s Compassionate Use Program, a time when unapproved medical treatments are the only options for patients with serious or life-threatening conditions.

Locke worked with Robert Montgomery, director of NYU Langone’s Transplant Institute, to perform Looney’s seven-hour surgery. Locke currently serves as chief of the Division of Transplantation at the U.S. Health Resources and Services Administration, which is part of the Department of Health and Human Services.

Locke said Tuesday that Looney will spend the next three months in New York City to be closely monitored before returning home to Alabama.

Looney received 10 gene-edited pig kidneys developed by United Therapeutics subsidiary Revivicor. Three pig genes known to trigger immune responses were removed, as well as the pig growth hormone receptor. Six human genes were added to reduce the likelihood of rejection.

Because of genetic differences between pigs and humans, researchers are turning to gene editing to make pig organs more compatible with humans. But there is controversy in the xenotransplantation field over how much gene editing is needed to make pig organs function long-term in humans. In Pisano’s surgery earlier this year, the NYU team used a donor pig that had a single gene edited — a knockout — to eliminate alpha-galactose from the surface of the pig’s cells. The sugar triggers rapid rejection of pig organs in humans. That donor pig also came from Revivicor.

The Massachusetts team took a different approach to Slayman’s surgery, choosing a pig from the biotech company eGenesis that had undergone 69 gene edits. Leonardo Riella, medical director of renal transplantation at Massachusetts General Hospital, said: “These differences highlight the continued evolution of xenotransplantation strategies and underscore the need for more extensive genetic modification to improve compatibility. Potential Benefits.