Apr 5, 2024 - Health

Pig kidney transplant raises hopes for clinical trials

Illustration of a medical diagram of kidneys against an abstract background.

Illustration: Shoshana Gordon/Axios

The success of the world's first pig kidney transplant could stoke large-scale clinical trials on implanting animal tissues in humans to help ease the organ shortage crisis.

Why it matters: Demand for donated organs is vast as transplants have rebounded post-pandemic and the nation's troubled human donor organ system goes through a major overhaul.

  • More than 103,000 people are on the national transplant waiting list and 17 die each day waiting for an organ transplant.

Driving the news: A 62-year-old Massachusetts man with end-stage kidney disease was discharged from Massachusetts General Hospital on Wednesday after becoming the first recipient of a genetically edited pig kidney.

  • He was the third xenotransplant patient, following two who received pig hearts when no other transplant options were available and who each died soon after.
  • The biotech firm that produced the pig with the donor kidney, eGenesis, is in talks with the Food and Drug Administration about clinical trials for pig kidney and pediatric heart transplants, along with using pig livers connected to recipients from outside the body, per Nature.
  • Experimental transplants are currently reserved for patients with life-threatening illnesses when no comparable treatment exists under the FDA's compassionate use protocols.
  • The kidney patient, Richard Slayman, received a transplanted human kidney in 2018 that began failing last year. He resumed dialysis but experienced complications requiring hospital visits every two weeks, Mass General said.

The latest case shows that, at least in the short term, the animal organs are safe and function as expected, Luhan Yang, one of the founders of eGenesis, told Nature.

  • There is a risk of infection from pig pathogens — something clinicians are monitoring Slayman for.
  • Muhammad Mohiuddin, the University of Maryland surgeon who led the first pig-heart transplant in 2022, told Nature that clinical trials could produce the necessary rigorous data about the safety and efficacy of xenotransplantation.

Between the lines: The successful procedure marks a "potential breakthrough" in helping minority patients access kidney transplants amid the donor organ shortage and other barriers they face in the medical system, said Winfred Williams, Slayman's nephrologist.

  • End-stage kidney disease rates are estimated to rise as much as 68% in the U.S. by 2030, according to research in the Journal of the American Society of Nephrology.
  • Massachusetts General itself has more than 1,400 patients on the waiting list for a kidney transplant, officials said. Some will die or get too sick to be transplanted due to the long waiting time on dialysis.

The donor kidney came from a pig with 69 genes that had been modified using CRISPR gene-editing technology, to improve compatibility with humans and eliminate the risk of infection.

  • The renal graft, combined with immunosuppressive treatment, supported survival for up to two years in macaques, researchers showed last year.
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