A genetically engineered pig kidney helped Towana Looney enjoy 130 days without the need for dialysis before the organ was removed last week. It’s the longest a human has ever lived with a pig organ, marking another step forward in the burgeoning field of xenotransplantation, or the practice of transplanting animal organs into humans.
Looney, a 53-year-old-woman from Alabama, had been on dialysis for nine years before she received the pig kidney transplant in late November, becoming only the third person to receive a kidney from a gene-edited pig while alive.
She left the hospital 11 days after surgery at NYU Langone Transplant Institute, staying at an apartment near the hospital so she could get checkups every day. But medical complications developed after months of stability, leading to the difficult decision to remove the organ on April 4.
“In early April, she had a reduction in renal function due to acute rejection. What triggered the rejection episode after a long period of stability is being actively investigated, but it followed a lowering of her immunosuppression regimen to treat an infection unrelated to the pig kidney,” Dr. Robert Montgomery, director of the NYU Langone Transplant Institute and chair of NYU Langone Health’s surgery department, said in a statement.
“The decision was made by Ms. Looney and her doctors that the safest intervention would be to remove the kidney and return to dialysis rather than giving additional immunosuppression. This preserves future possibilities for transplantation for her as knowledge and innovations progress,” he said.
United Therapeutics Corporation, the biotech company that developed the modified pig kidney – known as a UKidney – celebrated the bravery and enthusiasm Looney has shown throughout the xenotransplantation journey.
“One of the biggest challenges for transplant recipients – human-to-human or pig-to-human – is the prevention and management of infections while simultaneously balancing the level of immunosuppression medications required to prevent rejection, especially in the first months after surgery,” the company said in a statement.
“We will learn more about the circumstances that led to removal of the UKidney, but current evidence suggests that the UKidney functioned well up until the time of rejection, which appears to have occurred due to a reduction in immunosuppression while treating infection unrelated to the xenokidney,” they said. “We expect physicians at NYU will share their findings in a peer-reviewed publication in the future.”
Looney donated a kidney to help save her mother’s life in 1999 but later developed kidney failure after her remaining kidney was damaged by preeclampsia, a serious pregnancy complication involving persistent high blood pressure.
After years on the waitlist for an organ transplant, she began to develop problems associated with chronic dependence on dialysis. Without a donor match, she would die – but the complications she had developed made it more difficult to find one. When she heard about the option to try a pig kidney transplantation, she jumped at the chance to try it.
“Without a pathway to receiving a human kidney, she decided a gene-edited pig kidney was worth a try, and a lot of people rallied around her decision, including her husband and family,” Montgomery said at the time.
Looney is now back home in Alabama and says she’s grateful for the opportunity she had to participate in the research.
“For the first time since 2016, I enjoyed time with friends and family without planning around dialysis treatments,” she said in a statement. “Though the outcome is not what anyone wanted, I know a lot was learned from my 130 days with a pig kidney – and that this can help and inspire many others in their journey to overcome kidney disease. I remain thankful to all of the doctors and researchers at NYU Langone for all they are doing.”
More than 90,000 people in the United States are on the waitlist to receive a kidney transplant, according to data from the Organ Procurement and Transplantation Network, accounting for the vast majority of people waiting to receive an organ donation. The average wait time for a kidney is three to five years at most centers, and about 13 people die each day waiting.
Dialysis – a procedure to help remove waste and extra fluid from the blood – can be helpful in the short term but can do only 10% to 15% of what a healthy kidney does, and people on dialysis have a 50% chance of dying in the five years after they start the treatment, studies show.
The US Food and Drug Administration allows doctors to transplant organs from pigs into humans under what’s commonly known as “compassionate use,” which permits use of an experimental therapy or procedure if “comparable or satisfactory” options aren’t available.
Pigs’ organs are similar to humans’, and the speed of pigs’ reproduction means their organs can be procured quickly. Scientists can edit the genes of the pig to reduce the risk that a human body will reject its organ.
Looney was the first to receive a kidney with 10 gene edits, and United Therapeutics announced in February that it was cleared by the FDA to use this type of pig kidney in the first human clinical trials to study xenotransplantation. The company says they are in regular contact with the FDA about this and expect to perform the first of six initial transplants in people with end-stage kidney disease in the middle of 2025, with the intent of expanding the trial to a total of 50 patients.
Some experts foresee pig kidney transplant becoming an established option for patients within a decade, a major advancement that would be possible because of people like Looney.
“Towana’s willingness to endeavor into the unknown to help solve the nation’s organ shortage crisis will impact many more lives after her. We celebrate her tremendous courage and sacrifice,” Montgomery said. “She lived with a pig kidney longer than any other human in history, and the field has learned a great deal from her. Her contribution has furthered the hope and promise of genetically engineered pig organs as an alternative source to human organs.”
United Therapeutics echoed the sentiment.
“Mrs. Looney’s bravery has enabled major advancements in the field of xenotransplantation and adds to the foundational insights made possible by the contributions of other patients. Her case will continue to add to the scientific community’s understanding of xenotransplantation, from the initial transplant procedure to the post-transplant management of the xenograft,” the company said. “We keep Mrs. Looney and her family in our thoughts, and we wish her a speedy recovery.”