Porcine Kidney Bridges Patient to Human Transplant

A genetically edited pig kidney (EGEN-2784, eGenesis) supported a patient with end-stage kidney disease for 271 days without dialysis before he later received a human kidney, according to a report led by Massachusetts General Hospital investigators and published in The Lancet.

The patient underwent the xenotransplant on January 25, 2025, under a US Food and Drug Administration Expanded Access Investigational New Drug application. The porcine kidney functioned immediately, allowing him to remain off dialysis while the clinical team monitored renal function, rejection, anti-HLA antibodies, and possible transmission of porcine pathogens.

An early episode of T-cell-mediated rejection resolved with treatment, and investigators detected no porcine pathogen transmission. Graft function remained stable for approximately 6 months until immunosuppression was reduced in the setting of a non-zoonotic bacterial infection. Microvascular inflammation with endothelial injury subsequently developed and progressed to thrombotic microangiopathy, graft failure, and nephrectomy.

Eighty-two days after the xenograft was removed, the patient underwent human kidney transplantation. The human graft functioned immediately, and investigators found no evidence of sensitization during 231 days of follow-up.

The first-in-human report indicates that porcine kidney xenotransplantation may provide prolonged dialysis-free support and serve as a bridge to subsequent human kidney transplantation. The authors said the later microvascular injury may have involved mechanisms beyond conventional antibody-mediated rejection.

Source: Riella LV, Borges TJ, Rosales IA, et al. Porcine kidney xenotransplantation as a bridge to allotransplantation: a first-in-human study. Lancet. Published online September 3, 2026. doi:10.1016/S0140-6736(26)01295-X