Pig Liver Support: Can It Help Patients

How could a pig liver support someone with liver failure?

The approach, called extracorporeal liver cross-circulation, connects an external liver to the patient's circulation through a perfusion system. Its intended role is to help process substances that accumulate when the patient's liver cannot function adequately. In a July 2025 interview, the United Network for Organ Sharing described the possibility of buying time for recovery or transplantation. These remain treatment goals that require clinical evidence. [UNOS interview](https://unos.org/news/saving-lives-with-pig-livers-fda-approves-new-trial-with-a-spin-on-an-old-treatment/)

The comparison with kidney dialysis helps explain the setup, but liver support presents additional challenges. The liver processes waste and produces substances the body needs. Researchers must therefore assess which functions the external organ actually supplies. Removing unwanted compounds would be useful, but demonstrating adequate production of essential substances would answer a different, consequential question about how broadly the system can support a failing liver.

What evidence supports testing the pig-liver system?

On April 15, 2025, eGenesis and OrganOx announced FDA clearance of an investigational new drug application for the EGEN-5784 pig liver combined with an external circulation system. Their announcement described a study involving up to 20 intensive-care patients with acute-on-chronic liver failure who were ineligible for transplantation. The companies also reported four earlier perfusions involving deceased donors. The announced objectives included evaluating safety, system performance and clinical activity. [Company trial announcement](https://www.organox.com/news/egenesis-and-organox-announce-u-s-fda-clearance-of-ind-application-for-the-treatment-of-patients)

A University of Pennsylvania announcement in January 2024 described an initial experiment lasting 72 hours. Researchers reported physiological stability in the deceased donor and no signs of inflammation in the pig liver during that observation period. This was an important feasibility result, but a short experiment in a deceased donor cannot establish whether treatment helps a living patient recover or survive. Clinical interpretation must distinguish successful circulation through an organ from meaningful improvement in a person's illness. [University of Pennsylvania research announcement](https://www.eurekalert.org/news-releases/1031739)

What safety questions must researchers resolve?

Keeping the pig liver outside the body does not eliminate concerns about animal-to-human infection. The FDA's definition of xenotransplantation includes procedures in which human blood or other biological material contacts living animal tissue outside the body before returning to the recipient. The agency identifies both recognized and previously unidentified infectious agents as concerns, including infections that might become apparent only later. [FDA explanation of xenotransplantation](https://www.fda.gov/vaccines-blood-biologics/xenotransplantation)

FDA guidance addresses source-animal screening, product testing and clinical evaluation to reduce these risks. For patients and clinicians, the central question is whether any improvement in liver function translates into better outcomes with acceptable harms. A persuasive clinical assessment would need to examine complications, recovery and survival together. Early evidence that a system can function should guide further research, while decisions about wider use require evidence that patients benefit. [FDA guidance on xenotransplantation products](https://www.fda.gov/regulatory-information/search-fda-guidance-documents/source-animal-product-preclinical-and-clinical-issues-concerning-use-xenotransplantation-products)