United Therapeutics announces recent milestones for its heart and kidney xenotransplantation programs

United Therapeutics’ organ manufacturing efforts consist of seven investigational programs: xenoheart, xenokidney, xenothymokidney, regenerative lungs, 3D-printed lungs, 3D-printed livers, and 3D-printed kidneys. These groundbreaking programs are intended to address the ongoing shortage of transplantable organs for patients with end stage organ disease.

According to the U.S. Health Resources and Services Administration, around 110,000 Americans are currently waiting for an organ transplant, and more than 6,000 patients – 17 every day – die each year before receiving one. Almost 89,000 patients are waiting for kidneys, over 10,000 for livers, over 3,300 for hearts, and almost 1,000 for lungs, with many more patients suffering from end-stage organ failure who are ineligible for the strict organ transplant waiting list who could benefit from a readily available supply of organs on demand.

United Therapeutics initiated its xenotransplantation research work in 2011 and currently employs more than 50 scientists and support staff advancing this program. The company is currently finalizing construction of a $100 million clinical-scale designated pathogen free facility in Christiansburg, VA to support future clinical xenotransplantation studies with a capacity of approximately 125 organs per year.

To date, 10 xenotransplantation procedures using United Therapeutics' xenohearts and xenokidneys have been performed in living and brain-dead human recipients: two living human recipients of xenohearts, six brain-dead xenokidney/thymokidney recipients, and two brain-dead xenoheart recipients. United Therapeutics has built on its history of innovation in xenotransplantation with strong partnerships with top academic medical centers including the University of Maryland Medicine (UMM), NYU Langone Health (NYU), and the University of Alabama at Birmingham (UAB).

Second Successful Xenoheart Transplant Conducted at the University of Maryland Medical Center: In the second procedure of its kind, surgeons affiliated with UMM last Wednesday transplanted a UHeart from a 10-gene modified pig into Mr. Lawrence Faucette, under an emergency approval from the FDA. According to the transplant team, a xenoheart transplant was the only option available for Mr. Faucette, who has end-stage heart disease and was deemed ineligible for a traditional transplant with a human heart due to his pre-existing peripheral vascular disease and complications with internal bleeding. Mr. Faucette was facing near-certain death from heart failure.

United Therapeutics’ UHeart is a heart from a pig with 10 genetic modifications to support organ functioning in the human body. Six human genes were added to the pig genome to facilitate immune acceptance of the organ, while four genes were knocked out: three that contribute to porcine organ rejection in humans and one that can cause organ growth beyond what is normal for humans. United Therapeutics is also developing the UKidney™, a kidney from the same 10-gene modified pig.

“The second transplantation of a UHeart into a living person and the extended study of a UThymoKidney in a decedent, coupled with other ground-breaking research by our collaborators at the University of Alabama at Birmingham, University of Maryland Medicine, and NYU Langone Health, form the basis of knowledge we are sharing with the FDA ahead of commencing future clinical studies of xeno organs in humans,” said Leigh Peterson, Ph.D., Executive Vice President, Product Development & Xenotransplantation at United Therapeutics. “We look forward to continuing our dialogue with the FDA with the goal of starting clinical studies in 2025.”

Dr. Peterson continued: “We are grateful for the courageous contribution of Mr. Faucette and his family to the advancement of this important science. The entire United Therapeutics family is pulling for Mr. Faucette and hopeful for a smooth recovery.”

United Therapeutics is preparing for clinical trials of its xenoheart and xenokidney products, following completion of ongoing preclinical studies required by the FDA.

Xenokidney Demonstrates the Longest-Documented Case of Xeno Organ Function in a Human Body at NYU Langone Medical Center: In a 61-day study that concluded September 13th, surgeons at NYU Langone Medical Center evaluated the function of a UThymoKidney in what is now the longest-documented case of a xeno organ functioning in a human body. The kidney recipient, with his family’s consent, was a deceased 58-year-old man who had been on a ventilator after being declared dead by neurologic criteria before the xenotransplant. United Therapeutics’ UThymoKidney is a kidney from a one-gene modified pig along with the pig’s thymus. The gene that is inactivated is responsible for the synthesis of alpha-gal, a sugar on the surface of cells that can cause the immediate rejection of the organ in a human body. The pig’s thymus is intended to help teach the recipient’s immune system to recognize the kidney as “self” and prevent rejection.

“We at United Therapeutics congratulate our research collaborators at University of Maryland Medicine and NYU for these two historic achievements,” said David Ayares, Ph.D.,President and Chief Scientific Officer of United Therapeutics’ Revivicor subsidiary. “We also recognize the contributions of the patients and families associated with these procedures that help us move forward with this important science. In addition, I want to recognize the decades of work and dedication by the Revivicor team to bring this technology so close to its potential to revolutionize the way we treat end stage organ disease.”