Genetically Modified Pig Kidney Keeps Man Alive for Record Nine Months

The Clinical Timeline and Procedure

Tim Andrews underwent the xenotransplantation procedure in January 2025 after developing renal failure brought on by type 2 diabetes, according to medical teams at Mass General Brigham. The organ came from a Yucatan miniature pig and was genetically engineered to improve compatibility with the human immune system.

According to attending physicians, the animal organ functioned immediately as a temporary bridge while Mr. Andrews awaited a human donor kidney. He lived successfully with the genetically edited organ for 271 days before blood vessel damage progressed to organ failure. The pig kidney was subsequently removed, and Mr. Andrews transitioned to a short period of dialysis before receiving a kidney from a human donor.

Research Findings and Safety Data

The case represents the longest recorded dialysis-free survival following a pig kidney transplant in a living patient, according to the medical team. Researchers reported that no pig viruses or other pathogens were detected at any point during the 271-day period.

Dr. Leonardo Riella, lead author from the centre for transplantation sciences at Mass General Brigham, stated that the organ shortage remains the primary crisis in transplantation. According to Dr. Riella, xenotransplantation could eventually help address this gap by acting initially as a bridge off dialysis and potentially as a destination therapy once long-term durability is established.

Patient Experience and Daily Function

In a CNN documentary, Mr. Andrews described the transplant as a miracle that restored his daily independence. He reported being able to cook, vacuum, and take long walks with his dog Cupcake during the months the organ functioned.

Researchers noted that the findings support the viability of pig kidneys as a bridge for patients facing extended wait times for human organs, while emphasizing that further clinical studies are necessary to establish broader safety profiles.