Advancing potential for Future Patients. Mr. Bill Stewart ·

days with transplant and counting

On June 14, 2025, Bill Stewart, 54, became the second patient treated under the Multi-Patient Expanded Access Study and the third person worldwide to receive an EGEN-2784 genetically edited porcine kidney. 

Before his transplant, Bill had spent more than two years receiving dialysis three times per week. His O‑group blood type meant he faced a longer-than-average wait time for a human kidney, leaving him at risk of ongoing complications and declining health while waiting for a donor organ that might never arrive.

Bill’s transplant was performed at Massachusetts General Hospital by a multidisciplinary transplant team led by Dr. Leonardo Riella and Dr. Tatsuo Kawai. He was discharged just one week later, and immediately began living dialysis-free for the first time in years. Bill described the impact simply: ​“This transplant gave me a new lease on life. The compassion and intelligence of the MGH team has kept me safe every step of the way. I couldn’t be in better hands.”

Bill’s progress continues to inform the development of EGEN-2784 and helped support the FDA’s subsequent clearance of the IND for the product. His courage — and his trust in our science — is shaping the future of xenotransplantation and expanding what may soon be possible for more patients worldwide.