In a last-ditch effort to save his life, doctors at the University of Maryland Medical Center have transplanted a genetically modified pig heart into patient David Bennett, a 57-year-old handyman from Maryland. He's doing well three days after the highly experimental surgery - and is being monitored for immune system problems and other complications - but it's still too early to tell if the operation will work. Due to his condition, Bennett had also received a pig heart valve about a decade ago, which (along with pig skin grafts) are routinely used in humans.
Snapshot: "It was either die or do this transplant. I want to live. I know it's a shot in the dark, but it's my last choice," Bennett said a day before the nine-hour surgery. While he knew there was no guarantee the experiment would be effective, Bennett was ineligible for a human heart transplant or pump due to heart failure condition and an irregular heartbeat. The FDA, which oversees such experiments, allowed the xenotransplantation surgery under "compassionate use" emergency authorization, which is available when a patient with a life-threatening condition has no other options.
"If this works, there will be an endless supply of these organs for patients who are suffering," said Dr. Muhammad Mohiuddin, scientific director of the University of Maryland's animal-to-human transplant program. A total of 106,657 people are currently on the national transplant waiting list, and more than 6,200 patients die each year before getting one. More than 40,000 organ transplants were done in the U.S. in 2021, including a record 3,800 heart transplants.
New gene editing tools: Several biotech companies are developing pig organs for human transplant, with the heart used in the most recent operation coming from Revivicor, a subsidiary of United Therapeutics . The organ was modified to make it more acceptable to a human, including removing and inserting 10 genes to keep the heart from growing after transplant among other changes. The team at the University of Maryland Medical Center also used a new drug made by Kiniksa Pharmaceuticals to help prevent the organ from being rejected by the patient.