In a groundbreaking experiment, an Alabama woman lived for a record-setting 130 days with a pig kidney before doctors removed the organ due to signs of rejection. Towana Looney, who has battled kidney failure for nearly a decade, became the first person to live more than four months with a gene-edited pig kidney, offering researchers new hope in the long-running pursuit of animal-to-human organ transplantation.
A Patient Without Options
Towana Looney, a woman in her 50s from Gadsden, Alabama, had been on dialysis since 2016. Her immune system was abnormally reactive, making her ineligible for a traditional human kidney transplant. When the opportunity arose to participate in an experimental xenotransplant at NYU Langone Health in New York, she agreed to be part of what she called an “incredible research” effort.
On November 25, 2024, Looney underwent surgery to receive a kidney from a genetically altered pig. Scientists had modified the pig’s DNA to make the organ more compatible with the human body. The surgery was led by Dr. Robert Montgomery, a pioneer in the field of xenotransplantation.
A Functional Success—At First
For more than four months, the pig kidney worked. Looney was able to stop dialysis. She described herself during that time as “superwoman,” proud of the medical team and hopeful that her experience would help others.
“We did the safe thing,” Dr. Montgomery later explained to the Associated Press. “She’s no worse off than she was before the xenotransplant and she would tell you she’s better off because she had this four-and-a-half month break from dialysis.”
The kidney appeared to function well until early April, when signs of rejection emerged. On April 4, doctors removed the organ.
What Went Wrong?
The exact cause of the rejection is still under investigation. However, doctors believe a few factors may have contributed. Just before the rejection began, Looney had an infection related to her earlier time on dialysis. To help her fight the infection, doctors slightly reduced her anti-rejection medications, which suppress the immune system.
At the same time, her immune system was beginning to reactivate after the transplant. Dr. Montgomery believes the combination of these two events might have damaged the pig kidney, leading to rejection.
Rejection is a risk even with human transplants, and xenotransplants pose even greater challenges. While gene editing can reduce the chance of immediate rejection, doctors still need to determine the best combination of immune-suppressing drugs to keep the body from attacking the foreign organ over time.
A Major Step Forward
Although the pig kidney did not last forever, Looney’s 130-day experience is being called a significant achievement. Before her, only four Americans had received pig organs: two hearts and two kidneys. None of those organs lasted beyond 60 days, and all the patients died. Looney, by contrast, lived longer than anyone with a gene-edited pig organ and is now recovering back home.
Dr. Tatsuo Kawai of Massachusetts General Hospital, another expert in xenotransplantation, explained, “When we have more experience, we’ll know what kind of immunosuppression is really necessary for xenotransplant.”
Montgomery agreed, saying the future of xenotransplantation will be built step by step. “This is going to be won with singles and doubles, not swinging for the fence every time we do one of these,” he said.
A Glimpse of Hope
Looney’s story comes at a time when over 100,000 people in the U.S. are waiting for organ transplants, with kidneys being the most needed. Every day, around 17 people die waiting. Animal organs could one day help meet that demand, especially for patients who cannot receive human organs due to immune system complications.
While her time with the pig kidney ultimately ended in rejection, Looney remains hopeful about the bigger picture. “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 overcoming kidney disease,” she said.
Her case will help shape a rigorous clinical trial scheduled to begin this summer, as doctors continue exploring how to make xenotransplants a safe, lasting option for patients in need.
