Five patients at Massachusetts General Hospital have undergone successful xenotransplants with genetically engineered pig kidneys since March 2024, according to US biotech company Genesis. In three cases, the porcine organs functioned for over eight months without rejection or dialysis. The organs were grown in Yucatan miniature pigs, modified to remove rejection-causing proteins and add human compatibility genes.

Genesis CEO Mike Curtis stated the FDA has authorized an expanded trial of 33 patients starting early next year across up to 10 US transplant centres, targeting marketing approval by late 2029. Genesis is also collaborating with Japanese partner Por Med Tec for trials in Japan beginning 2028. Dr. Leonardo Riella, director of kidney transplantation at Mass General, called the progress "amazing" and noted the organs could serve as a bridge off dialysis or potentially as destination therapy. Patient Tim Andrews, 66, lived with a pig kidney for almost nine months before receiving a human donor organ, with subsequent tests showing no hindrance to the later transplant.

While experts like David Crosby of Kidney Research UK call the breakthrough "exciting," they caution that further research is needed to determine if the approach is safer than long-term dialysis. The advancement marks a significant shift from earlier heart-focused research to kidney-led clinical approval.