WORLD’S first successful pig kidney transplant Richard Slayman dead at 64 just weeks after successful record-breaking treatment

Slayman died on Saturday, only two months after the procedure was conducted using a pig kidney which had undergone 69 genomic edits.

Richard Slayman, 62, died on Saturday, only two months after the experimental pig kidney transplant procedure was conducted

Released from the hospital on April 6, Slayman reported having the ‘cleanest bill of health’ he could remember

At this time, there is no evidence to suggest his death was related to the transplant

Released from the hospital on April 6, Slayman reported having the “cleanest bill of health” he could remember reported local ABC news affiliate WCVB.

At this time, there is no evidence pointing to his death being related to the transplant.

Slayman underwent the surgery at Massachusetts General Hospital (MGH), in Boston on March 16 under Expanded Access Protocol “compassionate use” clearance.

This Expanded Access Protocol is only implemented when patients with serious life-threatening conditions have no other treatment options.

And the genetically modified pig kidney certainly was the last option for Slayman, after a long history of medical conditions and complications.

“I would rather get a rejection very early and get it treated and make adjustments rather than seeing it much later where it might go unnoticed for a couple weeks, at which point it might be too late,” explained Leonardo Riella, MGH’s medical director of kidney transplantation.

“It’s a bit like a wildfire; you want to extinguish it quickly before it gets out of control.”

After three days on a high dose of steroids, the rejection stabilized, as did the kidney, and Slayman was soon released.

In the months since his transplant, Slayman underwent blood and urine tests three times a week and doctor visits twice a week to monitor his status.


After the surgery, Slayman provided some insight into his perspective on the operation, citing a calling bigger than just himself as to why he agreed to move forward with the transplant.

“I have been a Mass General Transplant Center patient for 11 years and have the highest level of trust in the doctors, nurses, and clinical staff who have cared for me,” said Slayman.

“When my transplanted kidney began failing in 2023, I again trusted my care team at MGH to meet my goals of not just improving my quality of life but extending it.

“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 explained.

Dr. Winfred Williams, associate chief of the nephrology division at MGH, provided additional medical insight as to why his need for a kidney was imminent enough to consider experimental treatment.

“He would have had to wait five to six years for a human kidney. He would not have been able to survive it,” he explained at the time.

Joren C. Madsen, Director of the MGH Transplant Center reinforced the importance of Slayman’s contribution to medicine, further explaining how his consent to the surgery and bravery would help advance the field and save lives.

“[The surgery] would not have been possible without his courage and willingness to embark on a journey into uncharted medical history,” said Madsen.

“Mr. Slayman becomes a beacon of hope for countless individuals suffering from end-stage renal disease and opens a new frontier in organ transplantation.”

‘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 said of the surgeryCredit: AFP

The pig donor’s genes were changed with CRISPR-Cas9 technology, a tool used to edit genomes, allowing researchers to easily alter DNA sequences and modify gene functionCredit: AP

Slayman’s doctor recommended the experimental, first of its kind, surgery after his first human kidney transplant failed and various complications made dialysis