The first patient in the world to receive the transplant of a genetically-edited pig kidney has died, just two months after the procedure.

In a statement, the Mass General transplant team said they are "deeply saddened at the sudden passing of Mr. Rick Slayman. We have no indication that it was the result of his recent transplant. Mr. Slayman will forever be seen as a beacon of hope to countless transplant patients worldwide and we are deeply grateful for his trust and willingness to advance the field of xenotransplantation. We offer our heartfelt condolences to Mr. Slayman’s family and loved ones as they remember an extraordinary person whose generosity and kindness touched all who knew him.”

Slayman's family also issued a statement following his passing. “Our family is deeply saddened about the sudden passing of our beloved Rick but take great comfort knowing he inspired so many. Millions of people worldwide have come to know Rick's story. We felt – and still feel – comforted by the optimism he provided patients desperately waiting for a transplant. To us, Rick was a kind-hearted man with a quick-witted sense of humor who was fiercely dedicated to his family, friends, and co-workers. We are extremely grateful to his care team across Massachusetts General Hospital and Mass General Brigham, especially Dr. Williams, Dr. Kawai, and Dr. Riella, who truly did everything they could to help give Rick a second chance. Their enormous efforts leading the xenotransplant gave our family seven more weeks with Rick, and our memories made during that time will remain in our minds and hearts.

"After his transplant, Rick said that one of the reasons he underwent this procedure was to provide hope for the thousands of people who need a transplant to survive. Rick accomplished that goal and his hope and optimism will endure forever. His legacy will be one that inspires patients, researchers, and health care professionals everywhere. Our family asks for respectful privacy as we remember the beautiful soul of our beloved Rick.”

Slayman, 62, had been living with end-stage kidney disease. Surgeons from the Mass General Transplant Center conducted the four-hour-long surgery on Saturday, March 16. The procedure marked a major milestone in the quest to provide more readily available organs to patients.

The pig kidney was provided by eGenesis of Cambridge, Massachusetts, from a pig donor that was genetically-edited using CRISPR-Cas9 technology to remove harmful pig genes and add certain human genes to improve its compatibility with humans. Additionally, scientists inactivated porcine endogenous retroviruses in the pig donor to eliminate any risk of infection in humans. 

The successful procedure in a living recipient is a historic milestone in the emerging field of xenotransplantation – the transplantation of organs or tissues from one species to another – as a potential solution to the worldwide organ shortage. According to the United Network for Organ Sharing, more than 100,000 people in the U.S. await an organ for transplant and 17 people die each day waiting for an organ. A kidney is the most common organ needed for transplant, and end-stage kidney disease rates are estimated to increase 29-68% in the U.S. by 2030, according to literature published in the Journal of the American Society of Nephrology.