eGenesis Reports Sustained Kidney Function and Successful Human Transplantation Following Genetically Engineered Pig Kidney Transplants
eGenesis, a biotechnology company focused on developing genetically engineered organs designed for transplantation into humans, has announced encouraging clinical updates from its ongoing Expanded Access study of EGEN-2784, its lead genetically engineered porcine kidney candidate for patients with kidney failure. The latest findings provide additional clinical evidence supporting the potential role of xenotransplantation as an alternative or bridge to human donor organ transplantation amid a severe global shortage of kidneys.
Since March 2024, five patients with kidney failure have received EGEN-2784 kidney transplants through an Expanded Access program conducted in collaboration with the Mass General Brigham health system. According to the company, three of the five recipients have achieved sustained kidney function lasting more than eight months without requiring dialysis.
One patient has remained dialysis-independent for more than nine months, establishing what eGenesis describes as a new global record for a genetically engineered porcine kidney transplant. The patient continues to be followed as part of the study.
Perhaps most significantly, two of the five patients who received EGEN-2784 subsequently underwent successful transplantation with kidneys from human donors. These cases represent the first reported transitions from xenotransplantation to allotransplantation and provide important clinical insight into whether a genetically engineered animal organ can provide meaningful kidney function while preserving a patient’s opportunity to later receive a conventional human donor organ.
Xenotransplantation as a Potential Bridge to Human Transplantation
Kidney failure represents a major global healthcare challenge. For patients with end-stage kidney disease (ESKD), dialysis can sustain life, but it is associated with substantial clinical and quality-of-life burdens. Kidney transplantation is generally regarded as the preferred treatment for eligible patients because a successful transplant can improve survival and reduce the dependence on long-term dialysis.
The major limitation is the shortage of suitable human donor kidneys.
Thousands of patients remain on transplant waiting lists, while many others may never become eligible for transplantation or may experience prolonged waiting periods. For patients who are medically suitable, finding a compatible human organ at the right time can be difficult.
Genetically engineered animal organs are being investigated as a potential way to address this shortage. Xenotransplantation—the transplantation of organs between different species—has historically faced major biological barriers, including immune rejection and concerns surrounding compatibility and safety.
eGenesis has developed EGEN-2784 with multiple genetic modifications intended to address some of these challenges. The company’s latest clinical experience is aimed at determining whether these engineered organs can provide meaningful kidney function in human recipients.
The ability of two patients to subsequently receive human donor kidneys is particularly important because it suggests that xenotransplantation may potentially serve as an interim treatment rather than necessarily replacing conventional transplantation.
Five Patients Treated Under Expanded Access
Five patients with kidney failure have received EGEN-2784 kidneys since March 2024 under Expanded Access in collaboration with Mass General Brigham.
Three patients have experienced kidney function lasting longer than eight months without dialysis. One recipient has surpassed nine months of dialysis independence and remains in the study.
For patients living with kidney failure, extended periods without dialysis could have important implications. Dialysis requires regular treatment and can place significant demands on patients, caregivers, and healthcare systems. A functioning transplanted kidney has the potential to provide greater independence while reducing the burden associated with dialysis.
The clinical outcomes reported by eGenesis remain from an ongoing Expanded Access experience, and additional follow-up will be important to understand the durability, safety, and clinical performance of genetically engineered porcine kidneys over longer periods.
Nevertheless, the reported outcomes provide an important foundation for the company’s planned next stage of clinical development.
Patient Successfully Transitions to Human Donor Kidney
One of the most notable cases involved Tim Andrews, whose clinical experience was published in The Lancet. Andrews achieved approximately nine months of dialysis independence following transplantation with an EGEN-2784 kidney.
After the xenograft was removed, Andrews successfully received a human donor kidney 82 days later.
The sequence is significant because it demonstrates a potential pathway in which a genetically engineered porcine kidney could provide kidney function while a patient remains without access to a suitable human donor organ. If a compatible human kidney later becomes available, the patient may still be able to undergo conventional transplantation.
This possibility could change the way xenotransplantation is viewed within the broader transplant ecosystem. Rather than being considered only as a permanent alternative to human donor transplantation, an engineered animal kidney could potentially serve as a bridge for selected patients waiting for an allograft.
The two reported transitions to human donor kidneys provide initial clinical evidence that xenotransplantation does not necessarily eliminate future access to conventional transplantation.
EGEN-2784 Uses Multiple Genetic Modifications
EGEN-2784 is designed with three broad classes of genetic modifications intended to improve compatibility between the porcine organ and human recipients and support long-term kidney function.
The first modification involves the elimination of three glycan antigens. These antigens can contribute to rapid immune recognition and rejection of animal organs by the human immune system. Their removal is intended to reduce the risk of hyperacute immune rejection.
The second class involves the insertion of seven human transgenes. These modifications are designed to influence several biological pathways that can affect the performance of a transplanted organ. According to eGenesis, the transgenes are intended to regulate immune responses, reduce inflammation, improve coagulation compatibility, and regulate complement activation.
The third modification involves the inactivation of endogenous retroviruses. This approach is intended to enhance the safety profile of the engineered organ by addressing concerns associated with endogenous viral sequences present within the pig genome.
Together, these genetic changes are intended to make the porcine kidney more compatible with the human body and improve its potential to function following transplantation.
Leading Transplant Experts Oversee Clinical Program
The clinical study is being led by specialists from Massachusetts General Hospital (MGH), part of Mass General Brigham.
Leonardo V. Riella, M.D., Ph.D., Medical Director for Kidney Transplantation at MGH, serves as principal investigator and has overseen the clinical study and multidisciplinary transplant team.
Tatsuo Kawai, M.D., Ph.D., Director of the Legorreta Center for Clinical Transplant Tolerance, served as lead transplant surgeon. Nahel Elias, M.D., Surgical Director for Kidney Transplantation, also supported the surgical program.
Dr. Riella described the clinical experience as providing valuable information about the potential role of xenotransplantation for patients living with kidney failure.
“The experience with these patients is providing invaluable insight into the potential role of xenotransplantation for people living with kidney failure,” Riella said.
He noted that the sustained periods of dialysis independence are encouraging and emphasized the importance of the successful human kidney transplants following xenotransplantation.
According to Riella, these outcomes demonstrate that the approach may preserve future treatment options for patients and provide an important foundation for further clinical development.
FDA Clears EGEN-2784 for RESTORE Study
The latest Expanded Access results come as eGenesis prepares for a larger clinical study of EGEN-2784.
The U.S. Food and Drug Administration has cleared the company to conduct the Phase 1/2/3 RESTORE study, which is planned to evaluate EGEN-2784 in 33 patients with kidney failure.
The planned participants will be between 50 and 70 years of age and will be waitlisted for a human donor kidney transplant. eGenesis expects to initiate the RESTORE study during the first quarter of 2027.
The study is intended to provide more systematic clinical evidence concerning the safety, performance, and potential durability of the genetically engineered porcine kidney.
Moving from Expanded Access cases into a prospective Phase 1/2/3 study represents a significant development for the program. Clinical trial data from a larger patient population could help researchers better understand the benefits and risks associated with EGEN-2784 and determine how the technology might eventually fit into existing kidney transplantation practices.
Addressing a Global Organ Shortage
The need for alternative sources of transplantable organs is substantial. More than 800,000 Americans and millions of people worldwide are living with end-stage kidney disease.
Although kidney transplantation can substantially improve outcomes for eligible patients, the shortage of human donor organs remains a fundamental limitation.
In the United States, only approximately 28,000 kidney transplants were performed in 2024. Many patients therefore face extended periods on waiting lists or remain dependent on dialysis because a donor organ is not available.
The consequences can be serious. According to the information provided by eGenesis, the five-year mortality rate associated with dialysis is approximately 60%, underscoring the significant health burden faced by patients who cannot obtain a transplant.
The development of genetically engineered porcine kidneys could potentially introduce an alternative source of organs that is not dependent on the availability of human donors.
Mike Curtis, Ph.D., President and Chief Executive Officer of eGenesis, said the outcomes observed in the Expanded Access program provide important evidence that genetically engineered organs could potentially deliver sustained kidney function and dialysis independence while maintaining the possibility of subsequent human transplantation.
“Our goal is to make transplantation available to patients when they need it, without being constrained by the limited supply of human donor organs,” Curtis said.
The company believes the collective clinical experience will help support the development of EGEN-2784 as it moves toward the RESTORE study.
The next phase of clinical research will be closely watched because it could provide additional evidence about whether genetically engineered porcine kidneys can safely and effectively support patients with kidney failure over extended periods.
The reported nine-plus months of dialysis independence and the successful transition of two patients to human donor kidneys represent important milestones for the field of xenotransplantation. At the same time, the results come from a small number of patients, making continued monitoring and larger clinical studies essential.
If future studies confirm the safety and durability of EGEN-2784, genetically engineered kidneys could eventually become an important component of the transplant landscape. Such technology could potentially provide patients with a functioning organ when a human donor kidney is unavailable, reduce dependence on dialysis, and potentially serve as a bridge to conventional transplantation.
For eGenesis, the latest clinical updates mark another step toward its broader goal of developing human-compatible engineered organs. With FDA clearance for the RESTORE Phase 1/2/3 study and plans to begin enrollment in early 2027, the company is now preparing to advance EGEN-2784 into a more extensive clinical development program.
About eGenesis
eGenesis is a clinical-stage biotechnology company developing human-compatible engineered organs to address the severe global organ shortage. The Company’s proprietary genome engineering platform enables multiplex gene editing designed to address key barriers to xenotransplantation, including immune rejection and pathogen safety.
EGEN-2784, a genetically engineered porcine kidney, is the Company’s lead program. eGenesis is also developing products for liver and heart failure. To date, the Company has received FDA clearance to conduct clinical studies across its kidney and liver programs. eGenesis is headquartered in Cambridge, MA.