The US Food and Drug Administration has given the green light to two biotechnology companies for clinical trials that will transplant organs from genetically modified pigs to people with kidney failure. If they are successful, these studies could lead to the broader use of crossing transplantation, a dream of medical scientists for centuries.
One of the companies, United Therapeutics Corporation, will start testing it with six patients, but that number could eventually rise to 50. The other, Egenesis, said he would start with three patients and develop the study from there .
“We are introducing a transformative era into organ transplantation,” said Mike Curtis, President and CEO of Egenesis.
In the last three years, five patients have been known to receive pig organs designed by these companies – two who received hearts and three who received kidneys. But these surgeries were not part of a formal clinical trial. Most of the patients were strongly ill and their transplants are allowed because other treatment options were exhausted.
The biggest survivor to date is Towana Looney, a 53 -year -old woman from Alabama who received a pig of pigs at Nyu Langone Health in New York in November. The other four organs recipients, who were much more sick when undergoing transplants, died shortly after the procedures.
More than 550,000 Americans have kidney failure and require dialysis and about 100,000 of them are on a waiting list to receive kidney. But there is an acute shortage of organ donation, with fewer than 25,000 transplants made in 2023. Many people die while waiting.
Even if the genetically modified pig organs prove to be safe and effective, it is not clear what they will cost and whether they are covered by insurance.
The United Therapeutics study, which is expected to start Midyear, will start with six patients in dialysis for at least six months but have no other serious medical problems. There will be a three -month waiting period between each transplant so that doctors can learn from the results.
If the first six transplants are successful, the test will extend to include up to 50 participants in what is called a spectrum -free test – a type of study that combines traditional phase 1, phase 2 and phase 3 tests and can lead to approval immediately .
Patients will be monitored for 24 weeks and will have to agree on monitoring tactics for the rest of their lives, allowing researchers to control not only their health situations but also for pathogens that could cross the pigs to humans.
Critics have caused concerns about the possibility of well -known or unknown pathogens in pigs who will be thrown into the human population during these transplants, although the risk is considered small. Both companies increase their pigs in non -pathogens that adhere to strict bio -safety protocols and regularly examine animals for pathogens.
Medical ethics have also raised questions about how patients can fully consent to such experiments when there are so many unknown risks.
In a worse case scenario, the recipient of an animal’s organ “could be infected by a detected pathogen from the source of pigs,” said Christopher Bobier, an associate professor specializing in Bioethics and Health Policy at Central Michigan College of Medicine.
He also said that it was difficult to explain these risks to someone who deals with the exhaustive nature of kidney dialysis, which involves connecting with a dialysis machine for three to four hours a day, three times a week. “Saying not would be incredibly difficult,” Dr. Bobier said. “Complete the lifelong consequences of this decision would be even more difficult.”
The kidneys produced by United Therapeutics come from pigs who have undergone 10 gene treatment to improve the compatibility of their organs with human hosts: Six human genes were added and four pig genes turned off – one that restricts organ growth can cause human rejection.
Pigs egenesis have undergone 69 gene treatment, including changes in 59 genes to disable the viruses incorporated into the pig genome.
The Egenesis test will start with three patients with kidney failure who are unlikely to receive a human organ within five years, Dr. Curtis said. There will be a six -month waiting period between the first and second patients, and then a three -month stay after that before the third, the company said.
