World’s first: Boston hospital transplants a genetically edited pig kidney into a 62-year-old man

Boston has once again made medical history.

The renowned hospital Mass General Hospital announced Thursday the world’s first successful transplant of a genetically edited pig kidney into a 62-year-old Weymouth man living with end-stage kidney disease.

“Nearly seven decades after the first successful kidney transplant, our clinicians have once again demonstrated our commitment to provide innovative treatments and help ease the burden of disease for our patients and others around the world,” said Anne Klibanski, MD, President and CEO, Mass General Brigham.

On Saturday, a team of transplant surgeons at the teaching hospital completed a four-hour operation transplanting a genetically modified pig kidney into the human patient, identified as Richard “Rick” Slayman, doctors from MGH said at a press conference Thursday morning.

MGH said Slayman is “recovering well” and expected to be discharged soon.

The cutting-edge CRISPR technology was pivotal in this operation.

The pig kidney was provided by eGenesis of Cambridge 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,” the hospital added in a release.

“We are committed to revolutionizing the treatment of organ failure and transforming transplantation to a system that is more equitable for patients, where supply is no longer a barrier to access,” Mike Curtis, eGenesis CEO, said during the press conference.

Cross-species transplantation, Curtis said, is the “most scalable and sustainable approach” to delivering organs to every patient who needs one. The company’s vision is “a world in which no patient dies waiting for an organ,” the CEO said.

The breakthrough is critical to addressing “unequal access for ethnic minority patients,” who face systemic barriers resulting in wide health disparities in kidney transplants, said Winfred Williams, Associate Chief of the MGH Renal Division.

According to a 2023 review published in the National Library of Medicine, the incidence of end-stage renal disease, being put on the transplant waitlist and receiving a living donor transplants were lower for Black patients than White and other.

Slayman is a system manager at the Department of Transportation who has worked throughout his battle with diabetes and kidney failure, said Williams, who said he has gotten to know and treat the patient for over a decade. Slayman has had diabetes and hypertension for 30 years and received a human kidney transplant in 2018, which eventually failed.

“The real hero today is the patient, Mr. Slayman, as the success of this pioneering surgery, once deemed unimaginable, would not have been possible without his courage and willingness to embark on a journey into uncharted medical territory,” said Dr. Joren C. Madsen, director of the MGH Transplant Center.

“As the global medical community celebrates this monumental achievement, Mr. Slayman becomes a beacon of hope for countless individuals suffering from end-stage renal disease and opens a new frontier in organ transplantation,” the doctor added.

The Weymouth man said in a statement he had the “highest level of trust” in MGH.

“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,” Slayman said. “My nephrologist, Dr. Winfred Williams, MD and the Transplant Center team suggested a pig kidney transplant, carefully explaining the pros and cons of this procedure. 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.”

According to the United Network for Organ Sharing (UNOS), more than 100,000 people in the U.S. await an organ for transplant and 17 people die each day waiting for an organ, MGH said.

A kidney, the hospital added, is the most common organ needed for transplant, and end-stage kidney disease rates are estimated to increase 29-68 percent in the U.S. by 2030, according to literature published in the Journal of the American Society of Nephrology.

“When we saw the first urine output everyone in the operating room burst into applause,” said Tatsuo Kawai, Director of the Legorreta Center for Clinical Transplant Tolerance and Slayman’s primary transplant surgeon. “It was truly the most beautiful kidney I have ever seen.”