The first clinical trial to transplant genetically modified pig kidneys into patients with kidney disease is underway in the United States. If this trial successfully extends the survival period after transplantation, it is expected to provide a treatment alternative for many patients around the world waiting for organ transplants.
The U.S. Food and Drug Administration (FDA) announced on the 3rd (local time) that it has approved a clinical trial for transplanting genetically modified pig organs into patients with kidney failure. This trial is being conducted by the American pharmaceutical company United Therapeutics Corporation (UTC) and eGenesis.
UTC will target six patients who have undergone dialysis for at least six months and have no other medical abnormalities, and plans to increase the number of clinical participants to 50 if successful. eGenesis will also start with three patients and expand the target group. The first transplant is scheduled for mid this year, and patients will be monitored for 24 weeks post-transplant.
Kidney failure is a stage in which the kidney function that removes waste decreases to a point where normal recovery is not possible, indicating a kidney disease that requires dialysis and transplantation due to the loss of nerve function. It is considered a leading cause of death in the United States. According to the Centers for Disease Control and Prevention (CDC), more than 37 million people in the United States suffer from chronic kidney disease, and the number of patients registered on the kidney transplant waiting list is 100,000.
However, due to a shortage of donated organs, the number of transplant surgeries is declining. In 2023, only 25,000 kidney transplant surgeries were performed. While the survival period for patients needing kidney transplants is up to five years, there is a high risk of complications during that time. The National Kidney Foundation estimates that approximately 12 people die each day while waiting for a kidney transplant.
UTC is developing a kidney called 'UKidney' that can be transplanted into humans by altering the genes of pigs raised in a sterile environment. To enhance the compatibility between human hosts and pig kidneys, it undergoes 10 types of gene editing, adding six human genes and inactivating four pig genes.
Over the past three years, a total of five patients have received pig organs developed by UTC. Two received hearts, and three received kidneys. Among them, four patients did not survive more than two months post-transplant; however, a 53-year-old woman who received a pig kidney last November has overcome rejection and is living healthily to this day.
Leigh Peterson, vice president in charge of xenotransplantation at UTC, noted, "I believe that xenotransplantation can be a treatment alternative to dialysis," and stated, "Our goal through this clinical trial is to develop pig organs with high transplant success rates, providing new treatment alternatives so that many patients do not have to undergo lifelong dialysis treatment."
UTC plans to assess the safety by evaluating the rate of adverse reactions, serious adverse reactions, mortality from all causes, proteinuria, and the occurrence of zoonotic and opportunistic infections in patients after transplantation.
However, some scientists have raised concerns about the possibility of pathogens from pigs being transmitted to humans during the transplantation process.
Christopher Bovier, associate professor of bioethics and health policy at Central Michigan University, expressed concern through the New York Times (NYT), saying, "There is a risk of infection from pig organ pathogens that have not been previously discovered," and added, "Given the nature of kidney dialysis, where patients must be connected to a dialysis machine three times a week for several hours a day, it is difficult to assess the risks of transplanted animal organs."