Animal testing phase-out could derail pig organ
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- Robert F. Kennedy Jr. seeks to end all federally funded animal testing, citing poor predictivity of animal models; the CDC was told in November 2025 to phase out primate studies and is transferring animals to a sanctuary, and the NIH has stopped issuing funding opportunities exclusively for animal models.
- Of eight NIH-funded National Primate Research Centers, one has been shuttered and a second is exploring conversion to an animal sanctuary, according to the piece.
- Pig organ survival in primates has progressed from hours or days in the 1990s to weeks or months in the 2000s to years today, driven by two breakthroughs: the 1996 cloning of Dolly the sheep (enabling the first knockout pig) and CRISPR-Cas9 in 2012.
- From January 2022 to January 2025, clinicians transplanted two pig hearts and four kidneys into living humans under the FDA Expanded Access pathway; one eGenesis kidney survived nine months, bridging its recipient to a human transplant.
- Two multicenter pig-to-human kidney trials launched in 2024, with more than 70 patients expected to receive pig kidneys in the coming year; the author estimates genetically modified pig organs could reach the kidney and heart waitlists within five years.
- The surgeon argues that organ-on-chip, organoid, and AI models cannot replicate the complex physiology needed to test transplant rejection, and notes the U.K. lost its xenotransplantation industry in the early 2000s after animal-rights pressure shut down the required primate work.
Why it matters: The federal pullback arrives as xenotransplantation is within five years of reaching the 70-patient kidney trial stage and the 100,000-plus U.S. patients on organ waitlists; the U.K.'s loss of the field to the U.S. in the 2000s is a concrete precedent showing that countries abandoning primate research cede the science to competitors, and the 70 scheduled transplants in the next year represent the first pipeline at risk of stalling.
