United Therapeutics (NASDAQ:UTHR) has cleared a primary safety hurdle in its ambitious effort to manufacture biological alternatives to human organs, reporting that its bioengineered external liver supported critically ill patients without serious adverse effects.
The Silver Spring, Maryland-based biotech announced Monday that its Phase 1 study of miroliverELAP met its primary endpoint of patient survival during treatment.
The device, developed by United’s subsidiary Miromatrix Medical, was tested on five patients suffering from acute liver failure (ALF) who were not candidates for traditional transplants.
Unlike a mechanical dialysis machine, miroliverELAP utilizes a "bioengineered" approach.
Scientists take a pig liver, strip it of its original cells to leave a scaffold, and then "re-seed" that scaffold with human liver and endothelial cells.
This external organ then functions as a temporary bridge, providing vital filtration and metabolic support to give a patient’s native liver time to recover.
The five participants in the open-label study were treated continuously for at least 44 hours.
United Therapeutics reported no unexpected serious adverse events attributable to the device during a 32-day follow-up period.
While the sample size is small, the results validate a platform that could eventually expand to fully transplantable organs.
“This study provides early evidence that miroliverELAP has the potential to provide liver support for patients experiencing ALF,” said Jeff Ross, President of Miromatrix.
He noted that the therapy targets a desperate patient population, as roughly 30% of ALF patients currently die because they are ineligible for a transplant or cannot find a donor in time.
The success of the liver trial bolsters the broader strategy of United Therapeutics CEO Martine Rothblatt, who has transformed the company from a pulmonary-disease specialist into a leader in synthetic and xenotransplantation organ manufacturing.
The company is currently pursuing four different organs—hearts, kidneys, livers, and lungs—across three distinct technological platforms.
Beyond the external liver, Miromatrix is also working on "mirokidney," a fully transplantable bioengineered kidney using the same decellularization technology.
Detailed data from the liver safety study is expected to be published in the second half of 2026.