October 9, 2025

expert reaction to study on a modified pig liver being transplanted into a living person for the first time

A study published in the Journal of Hepatology looks at a genetically engineered pig liver transplanted into a living person for the first time. 

Comment provided by our friends at the Spanish SMC:

Dr Beatriz Domínguez-Gil, Director of the National Transplant Organisation, Spain, said:

“This is the first auxiliary liver transplant from a genetically modified pig (with 10 genetic modifications) in a patient. Therefore, it is the first performed for therapeutic purposes. To date, two cases of liver xenotransplantation have been published (one in China and one in the US) in brain-dead individuals, where the timeframe for evaluating graft function is limited.

“In this case, it was shown that the liver was able to function and support the patient for 38 days, with no evidence of rejection. However, the patient eventually developed xenotransplant-related thrombotic microangiopathy, requiring graft resection. Ultimately, the patient died on day 171.

“We can say that this represents a new step in the advancement of xenotransplant therapy, which continues to progress in clinical development, but it also highlights the significant obstacles that remain to be overcome, such as the serious complication observed in this patient.

“At the National Transplant Organization of Spain (ONT), we insist that these transplants are experimental. Further work is needed to perfect the genetic modifications carried out, improve the immunosuppression used, and attempt to identify and address any complications that may develop early. Ideally, this should be done in properly designed clinical trials to evaluate their efficacy and safety in the short, medium, and long term. However, these cases allow us to glimpse a future in which xenotransplantation is a clinical reality as a bridge therapy (particularly in the case of the liver) or as a destination therapy.

“I would like to add that, according to data from the Global Observatory on Donation and Transplantation, managed by the ONT as a WHO collaborating center, in 2024, in Europe alone, there were a total of 22,215 patients on the waiting list for a liver transplant, and only 11,019 received the transplant. Furthermore, in these countries, 2,314 patients died on the waiting list for a liver transplant.”

‘Genetically engineered pig-to-human liver xenotransplantation’ by Beicheng Sun et al. was published in Journal of Hepatology at 05:01 UK time on Thursday 9 October 2025. 

Declared interests

no reply to our request for DOIs was received.