Organ xenotransplantation: a long-standing ambition now promising1
Press release from the French National Academy of Medicine
May 14, 2025
In France and around the world, the shortage of human transplants (allografts) results each year in many deaths among patients on the organ transplant waiting list.
Recent advances in ‘molecular bioengineering’ have allowed, in the United States and China, the creation of transgenic pigs designed for human organ transplantation (xenografts), aimed at overcoming the immunological and infectious (particularly retroviral) obstacles that led to the 1999 European moratorium. Several recent kidney (1), heart (2) and liver (3) xenografts have shown encouraging results. Two clinical trials concerning transgenic pig kidney transplants, validated by the Food and Drug Administration, began in January of this year in the United States.
Despite these encouraging results, there are still many hurdles to overcome to make organ xenotransplantation a real alternative to allotransplantation, mainly concerning the production of transgenic pigs in ‘pharmaceutical’ farms and the control of xenograft rejection (production of low immunogenicity grafts and development of suitable immunosuppressive treatments). In France, some teams have assets in these areas (4,5), as well as experience in biotechnologies adapted to the production of pig xenografts (6).
Thus, if France and Europe are to embark fully on this path and avoid a dropout in biomedical sciences, as well as being subject to constraints in terms of access to xenografts, several conditions must be met in terms of supporting their research teams, defining the ethical and regulatory framework for the use of xenografts, and addressing the anthropological questions raised by this disruptive innovation.
Faced with the new promises offered by organ xenotransplantation and the challenges it poses, the French academy of medicine, which recently held a plenary session on the subject and published a dedicated report (7), calls for the implementation of a national ‘xenotransplantation’ plan and recommends:
– To invest in a massive, urgent and coordinated manner in xenograft research rejection prevention, social sciences and humanities research;
– To facilitate the creation in France of transgenic pigs and a ‘pharmaceutical’ farm capable of raising them, with respect for animal welfare, to supply organs under conditions complying with health safety requirements;
– To complete, from now on, the regulatory provisions allowing organs and tissues from transgenic pigs to be used in humans in France;
– To define an ethical and societal framework for the use of organs from transgenic pigs so that, in a context of shortage of allografts, their use, if made possible, offers an additional opportunity to patients.
1 Press release from the Academy’s Rapid Communication Platform.
References
1) Montgomery R.A., Stem J.M., Lonze B.E. et al., Results of two cases of pig-to- human kidney xenotransplantation, N Engl J Med, 2022, 386:1889-98.
2) Griffith B.P., Goerlich C.E., Singh A.K. et al., Genetically modified porcine-to-human cardiac xenotransplantation, N Engl J Med, 2022, 387: 35-44.
3) Tao K.S., Yang Z.X., Zhang X. et al., Gene-modified pig-to-human liver xenotransplantation, Nature, 2025, Online 26 March. DOI: 10.1038/s71586-025-08799.
4) Loupy A., Goutardier V., Giarraputo A. et al., Immune response after pig-to-human kidney xenotransplantation: a multimodal phenotyping study, Lancet, 2023, 402 (10408):1158-69.
5) Le Bas-Bernardet S., Blancho G., Progress in Porcine kidney transplantation to non-human primates, Transpl Int, 2025, Feb 14;38: 14003.
6) Viklicky O., Slatinska J., Janousek L. et al., First-in-human Study with LIS1, a Next-generation Porcine Low Immunogenicity Antilymphocyte Immunoglobulin in Kidney Transplantation, Transplantation, 2024 Jul 1; 108(7): e139-e147.
7) Lebranchu Y. and the ‘Xenografts’ Working Group of the French national academy of medicine. «Les xénogreffes d’organes, de tissus et de cellules. Quelle place pour la France? » (Organ, tissue and cell xenografts. What role for France? 2025 Report to be published in the Bulletin de l’Académie nationale de médecine).
PRESS CONTACT: Virginie Gustin +33 (0)6 62 52 43 42 virginie.gustin@academie-medecine.fr ACADÉMIE NATIONALE DE MÉDECINE, 16 rue Bonaparte – 75272 Paris cedex 06 Site : www.academie-medecine.fr / Twitter : @Acadmed
