Downtown Silver Spring-based biotechnology company United Therapeutics recently announced a groundbreaking achievement: on April 12th, the world’s first successful UThymoKidney pig-to-human kidney transplant was performed.
The pioneering UThymoKidney transplant procedure represents several historic firsts in the field of transplantation:
- The first-ever transplant of a xenothymokidney into a living human recipient;
- The first-ever combined mechanical heart pump and organ transplant; and
- The first-ever xenotransplant into a living human using only FDA-approved immunosuppressive medicines.
The procedure follows two successful pig-to-human heart transplants conducted by United Therapeutics in 2022 and 2023.
The UThymoKidney transplant was authorized by the U.S. Food and Drug Administration (FDA) in White Oak under the expanded access pathway and performed by surgeons at NYU Langone Health, led by Dr. Robert Montgomery. The recipient, 54-year-old Lisa Pisano from Cookstown, N.J., suffered from both heart and kidney failure, disqualifying her from traditional human organ transplant waiting lists due to a combination of chronic medical conditions and a lack of available human organs.
“I was at the end of my rope,” Pisano told The Associated Press last month. “I just took a chance. And you know, worst case scenario, if it didn’t work for me, it might have worked for someone else and it could have helped the next person.”
According to a UT press release, UThymoKidney is an investigational-stage xenokidney derived from a genetically modified pig with a single edit, combined with tissue from the same pig’s thymus. The thymus tissue aims to condition the recipient’s immune system to recognize the UThymoKidney as “self,” reducing the likelihood of rejection.
The single genetic modification in the pig involves the inactivation, or “knock-out,” of the gene responsible for synthesizing alpha-gal, a sugar on the surface of cells that can trigger immediate organ rejection when transplanted into the human body. Materials derived from this modified pig are referred to as GalSafe® by United Therapeutics, as they do not contain detectable levels of alpha-gal.
The GalSafe pig was developed by Blacksburg, Va.-based UT subsidiary Revivicor, Inc., and was approved by the FDA in December 2020 for use as human food or as a potential source for biomedical purposes, marking the first investigational biomedical use in a living human.
According to the U.S. Health Resources and Services Administration in Rockville, 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. With over 89,000 patients waiting for kidneys, close to 10,000 for livers, over 3,400 for hearts, and almost 1,000 for lungs, the need for a readily available supply of organs on demand is critical, UT said.
“I am pleased and impressed that decades of research into expanding the supply of kidneys have resulted in this historic, successful xenokidney transplant using United Therapeutics’ gene editing and thymokidney technology,” said Dr. Louis Sullivan, Secretary of the United States Department of Health and Human Services in President George H.W. Bush’s administration, member of the United Therapeutics Board of Directors, and Chair of its Scientific Advisory Board.
“I am so proud of the many scientists and surgeons working with United Therapeutics on its xenotransplantation programs,” said Gov. Tommy Thompson, Secretary of the United States Department of Health and Human Services in President George W. Bush’s administration and member of United Therapeutics’ Board of Directors. “This major breakthrough is a revolutionary step forward in our quest to create an unlimited supply of transplantable organs.”
United Therapeutics’ organ manufacturing efforts encompass four platforms – xenotransplantation, regenerative medicine, 3D organ bioprinting, and bio-artificial organs – targeting four different organs: hearts, kidneys, livers, and lungs. These groundbreaking programs aim to address the ongoing shortage of transplantable organs for patients with end-stage organ disease.
The company initiated its xenotransplantation research work in 2011 and currently employs close to 50 scientists and support staff advancing xenotransplant science with three different organ programs: the UHeart xenoheart, the UThymoKidney, a one-gene modified kidney and thymus, and the UKidney, a 10-gene modified kidney.
This year, United Therapeutics opened the world’s first clinical-scale designated pathogen-free facility in Christiansburg, Va., with a capacity of approximately 125 organs per year to support future clinical xenotransplantation studies.
To date, 11 xenotransplantation procedures using United Therapeutics’ UHearts, UThymoKidneys, and UKidneys have been performed in living and brain-dead human recipients, including two living human recipients of UHearts, one living recipient of a UThymoKidney, six brain-dead UKidney and UThymoKidney recipients, and two brain-dead UHeart recipients. The company has built strong research collaborations with top academic medical centers, including NYU Langone Health, the University of Maryland Medicine, Johns Hopkins Medicine, and the University of Alabama at Birmingham.
UT is preparing for clinical trials of its xenokidney, xenothymokidney, and xenoheart products after completing ongoing preclinical studies required by the FDA.
Meanwhile, the company continues to double down on downtown Silver Spring, having signed an ambitious $100 million expansion agreement with Montgomery County last year.
The agreement includes a land-swap deal, which will facilitate the construction of a new 675-space parking garage at 8615 Georgia Ave., in exchange for the Spring-Cameron Garage. United Therapeutics also commits to providing land and resources for a new data fiber hub while relocating the Department of Transportation’s parking operations facility to 9150 Brookville Road.
The Georgia Ave. site also designates a plot for a forthcoming affordable housing project. Upon completing the new garage, United Therapeutics will convey the Georgia Ave. site ownership to the county. In contrast, the Spring-Cameron Garage site ownership will transition to UT to facilitate its anticipated growth.
As part of the ownership transfer conditions, United Therapeutics must invest at least $50 million within fifteen years for any new facility on the site. The property disposition protocol requires public engagement and County Council endorsement after the County Executive certifies the property’s lack of further utility.
The county must also ensure its property is sold for its full market value.
Since its initial commercial sale in 2002, United Therapeutics has experienced an average annual revenue growth exceeding 20 percent. The company transitioned to a Public Benefit Corporation in 2021 and achieved nearly $2 billion in revenues by 2022.
In 2002, the county sold land in downtown Silver Spring to UT to establish its corporate headquarters at 1040 Spring Street. Subsequently, in 2015, another parcel on Spring Street was sold to the company to develop its environmentally sustainable, LEED Platinum-certified Unisphere expansion, renowned as the world’s largest site-powered net-zero commercial office building.
Completed in 2018, the Unisphere campus employs 230 individuals and focuses on biotechnology, specializing in marketing therapeutics for rare diseases and creating manufactured organs for transplant to assist patients with end-stage organ diseases. United Therapeutics’ adjacent DDOMAL facility produces Unituxin, a monoclonal antibody-based orphan drug treatment for pediatric neuroblastoma.
Further expanding its footprint in downtown Silver Spring, the company acquired office buildings at 8808 Cameron St. in 2018 and 8905 Fairview Rd. the following year.
Currently, UT is expanding the Unisphere campus, having procured the Hampton Inn/Homewood Suites dual-brand hotel in late 2021.
Photo: “United Therapeutics 06” by Farragutful is licensed under CC BY-SA 4.0. / United Therapeutics Graphic