A 62-year-old man has died months after becoming the world’s first living recipient of a genetically edited pig kidney transplant, hailed as a medical milestone.

Rick Slayman received the kidney at Massachusetts General in March after he had been diagnosed with end-stage kidney disease last year. The hospital emphasized there is no indication his death was a result of the transplant.

After undergoing the four-hour surgery at the recommendation of his doctors, Slayman, a manager with the Massachusetts Department of Transportation, was discharged from the hospital in April. After the surgery, doctors said they believed the new kidney could last years, but acknowledged there are many unknowns in animal-to-human transplants.

“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,” Massachusetts General said in a statement.

“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 described him as a kind man who was fiercely dedicated to the people in his life.

“Our family is deeply saddened about the sudden passing of our beloved Rick but take great comfort knowing he inspired so many,” a family statement said. “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.”

Slayman had been a patient in the hospital’s transplant program for 11 years, he previously said in a statement. He received a kidney from a human donor in 2018, after living with diabetes and high blood pressure for many years. The kidney began to show signs of failure five years later, and he resumed dialysis in 2023.

“I saw it not only as a way to help me, but a way to provide hope for the thousands of people who need a transplant to survive,” Slayman wrote in the statement.

Dr. Tatsuo Kawai, director of the Legorreta Center for Clinical Transplant Tolerance, performed the groundbreaking operation in March to a round of applause in the operating room.

The need for organs far exceeds the number available in the US. According to the Organ Procurement and Transplantation Network, there are more than 100,000 people currently waiting for an organ donation.

Experts have long been researching how to safely and successfully transplant animal organs into people, which they say could help solve the organ shortage.

Before Slayman’s transplant, just two transplants using pig organs had been completed – both heart transplants performed under compassionate use. Both patients died weeks after receiving the hearts.

EGenesis, the biotech company providing the genetically edited pig kidney, called Slayman “a true pioneer” in a statement late Saturday night.

“We are profoundly grateful to Mr. Slayman and his family and we will honor his legacy and invaluable contribution to science and medicine by continuing our efforts to advance xenotransplantation for the millions of patients globally in need of lifesaving organs,” the company added.

Slayman’s family also thanked his care team at across Massachusetts General in a statement.

“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,” his family said.