Second man receives genome-edited pig's heart

A US man has received the second-ever transplant of a pig heart.

Lawrence Faucette was suffering from terminal heart disease but was not eligible for a human heart transplant because of other existing conditions. The operation was performed at the University of Maryland Medical Centre in Baltimore by the same team that was also involved in the first such transplant (see BioNews 1128).

'My only real hope left is to go with the pig heart, the xenotransplant,' said Mr Fawcette prior to the operation.

He is reported to be recovering after the surgery on 20 September. His heart and lungs are working without support, and he is able to communicate.

The heart was grown in a donor pig in which ten genes had been edited: three genes that trigger the human immune system to reject pig organs were knocked out, and a further six were inserted to promote acceptance. An additional gene was knocked out to prevent the pig heart from growing excessively in the human host. In addition, Fawcette is receiving a new antibody drug in combination with anti-rejection drugs to prevent his immune system from reacting against the organ.

The first transplant using a pig heart took place in January 2022. Like Fawcette, the patient – David Bennett – had been in the last stages of heart failure and was ineligible for a human donor organ. Bennett died of heart failure two months after the surgery, although his body did not initially reject the heart.

The heart was later found to contain traces of the porcine cytomegalovirus (pCMV), found in pigs, although it was not established whether this had been the ultimate cause of death (see BioNews 1144). A new and more sensitive test, not available at the time of Bennett's surgery, was used to rule out the presence of pCMV in the heart Faucette received.

'We are once again offering a dying patient a shot at a longer life, and we are incredibly grateful to Mr Faucette for his bravery and willingness to help advance our knowledge of this field,' said surgeon Professor Bartley Griffith, who performed both transplants.

The transplant was conducted under an emergency compassionate use pathway granted by the US Food and Drug Administration (FDA).

'The FDA used our data from [preclinical research], as well as our experience with the first patient, to determine that we were ready to attempt a second transplant in an end-stage heart disease patient who had no other treatment options,' said Professor Muhammad Mohiuddin, director of the Cardiac Xenotransplantation Programme.

The team hope that the use of pig organs could help to address the shortage of organ donors in future. Two separate research groups in the USA recently reported the successful transplantation of a pig kidney into a human (see BioNews 1203).