After a monkey with a genetically modified pig kidney lived for over two years, researchers declared that this marked a significant advancement in the field of organ transplantation.
The research is the most recent to come out of Harvard Medical School and the US biotech company eGenesis. Scientists there believe that genetically modified pigs could help address the global scarcity of organ donors for patients suffering from organ failure.
The “extraordinary milestone” gave hope for the strategy, according to eGenesis CEO Dr. Michael Curtis, and “may pave the way for better outcomes for countless individuals in need of lifesaving organ transplants.”
The question of whether animal organs could ever function correctly and safely in humans without the patient’s immune system rejecting them has been the subject of decades of research, but the difficulties have been enormous.
In the most recent experiment, Yucatan miniature pigs were given kidney transplants into macaques after the researchers modified their genes using a gene-editing program called Crispr. Genes were modified in order to eliminate pig viruses that might activate in recipients and prevent organ rejection.
The scientists report how 21 monkeys fared after having their kidneys removed and having a single genetically altered pig kidney implanted in the journal Nature. When three genes that cause immune rejection were disabled in the kidneys, monkeys usually only lived for twenty-four days. However, the monkeys survived seven times longer—typically for 176 days—after the scientists introduced seven human genes that lower inflammation, blood clotting, and other immunological responses.
The researchers report that one monkey with the transplanted organ lived for over two years, or 758 days, when combined with immune system suppression treatment.
According to Curtis, eGenesis is on track to meet the US Food and Drug Administration’s requirement that the company see at least 12 months of animal survival before beginning a clinical trial in humans because at least some of the monkeys have survived for a long time.
Curtis stated, “We are very close to our destination.” “There just aren’t enough kidneys for everyone.” We believe that this is the only workable short-term fix.
Because the kidneys of Yucatan miniature pigs are similar in size to those of an adult human, the team uses these animals as donors. During the two to three month period in the monkey trial, the kidneys were transplanted when the organs were significantly smaller.
Because “they are a better match,” scientists expected the modified pig organs to function better in humans than in monkeys, according to Prof. Tatsuo Kawai, an author on the study from Harvard Medical School.
So far, two humans have benefited from heart transplants from pigs. In 2022, David Bennett, the first, passed away two months following surgery. On September 20, this year, 58-year-old Lawrence Faucette, who had end-stage heart disease, received a new heart and is currently recuperating.
Genetically engineered pig organs ought to go through human trials, according to Professor Muhammad Mohiuddin of the University of Maryland School of Medicine, who was involved in the groundbreaking heart transplant procedures.
In an accompanying editorial, he stated, “It is time for clinical translation of this vital technology, which has the potential to save lives that would otherwise be lost to the shortage of human organs.”
Preclinical models of non-human primates still have a lot to teach us. However, clinical trials—which enroll patients who have been turned down for all other forms of treatment—will be the ones that actually advance our knowledge of this amazing process and contribute to the technology’s realization.
Although he described the work as a “groundbreaking achievement,” King’s College London professor Dusko Ilic added, “There is still a long way to go before this strategy could be used in clinical trials.”
