Patient Dies Weeks After Kidney Transplant From Genetically Modified Pig

Richard “Rick” Slayman, who made history at age 62 as the first person to receive a kidney from a genetically modified pig, has died about two months after the procedure.

Massachusetts General Hospital, where Mr. Slayman had the operation, said in a statement on Saturday that its transplant team was “deeply saddened” at his death. The hospital said it had “no indication that it was the result of his recent transplant.”

Mr. Slayman, who was Black, had end-stage kidney disease, a condition that affects more than 800,000 people in the United States, according to the federal government, with disproportionately higher rates among Black people.

There are far too few kidneys available for donation. Nearly 90,000 people are on the national waiting list for a kidney.

Mr. Slayman, a supervisor for the state transportation department from Weymouth, Mass., had received a human kidney in 2018. When it began to fail in 2023 and he developed congestive heart failure, his doctors suggested he try one from a modified pig.

“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,” he said in a hospital news release in March.

His surgery, which lasted four hours, was a medical milestone. For decades, proponents of so-called xenotransplantation have proposed replacing ailing human organs with those from animals. The main problem with the approach is the human immune system, which rejects animal tissue as foreign, often leading to serious complications.

Recent advances in genetic engineering have allowed researchers to tweak the genes of the animal organs to make them more compatible with their recipients.

The pig kidney that was transplanted into Mr. Slayman was engineered by eGenesis, a biotech company based in Cambridge, Mass. Scientists there removed three genes and added seven others to improve compatibility. The company also inactivated retroviruses that pigs carry and could be harmful to humans.

“Mr. Slayman was a true pioneer,” eGenesis said in a statement on social media on Saturday. “His courage has helped to forge a path forward for current and future patients suffering from kidney failure.”

Mr. Slayman was discharged from the hospital two weeks after his surgery, with “one of the cleanest bills of health I’ve had in a long time,” he said at the time.

In a statement published by the hospital, Mr. Slayman’s family said he was kind, quick-witted and “fiercely dedicated to his family, friends and co-workers.” They said they had taken great comfort in knowing that his case had inspired so many people.

“Millions of people worldwide have come to know Rick’s story,” they said in the statement. “We felt — and still feel — comforted by the optimism he provided patients desperately waiting for a transplant.”