Bioethics Forum Essay
Myopic View of Xenotransplantation
The news media significantly influence public perceptions of medical innovation. How cutting- edge medical innovation is presented—what receives attention and what does not receive attention—is ethically relevant. A report last week in the New York Times of a pig heart transplant performed at the University of Maryland Medical Center exemplifies a common myopic view of xenotransplantation research. The article describes the case of a 58-year-old Navy veteran with end-stage heart disease, too sick to qualify for a human organ transplant, who received instead a genetically modified pig heart—the second patient to undergo this experimental surgical intervention. The patient appears as a heroic volunteer, helping to advance science in the hope of a long shot at extended survival.
The innovative nature of xenotransplantation gets prominent attention. In a breathless tone, the article’s author writes, “In recent years, the science of xenotransplantation has taken huge strides with gene editing and cloning technologies designed to make animal organs less likely to be rejected by the human immune system.” The pig donor, supplied by the for-profit company Revivicor, had 10 genetic modifications. The patient also received an experimental antibody treatment. In general, the news media approaches xenotransplantation as an irresistible technological frontier—one that is driven by scientific curiosity and prestige, and the potential of substantial future revenue flowing into biomedical companies and transplant centers.
As is typical of news stories concerning xenotransplantation, this article draws attention to the more than 100,000 Americans on the transplant waiting list, most of whom are seeking a new kidney. However, only 25,000 kidneys are transplanted in the United States each year. No effort is made to place this set of facts about organ donation and transplantation into a population health perspective. Of course, it is lamentable that approximately 6,200 Americans die each year while awaiting an organ transplant. But this represents only 0.2% of the approximately 3.2 million Americans who died in 2022.
Moreover, no mention is made of the prospect of preventing end-stage chronic disease, which in the case of kidney disease gives rise to the need for expensive and burdensome dialysis and organ transplants. Preventive efforts include enhanced educational and policy interventions to promote healthy diets and lifestyles and greater uptake of drug treatments to control hypertension and diabetes. Although lacking in scientific prestige, the fascination with technological innovation, and the prospect of substantial profit, promoting prevention holds promise for reducing the incidence, or ameliorating the progression, of chronic diseases.
The New York Times article reports that the Food and Drug Administration gave “compassionate use” emergency approval for this xenotransplantation intervention. But there is no mention of the compassionate alternative of palliative care and whether this was explored with the patient and his family.
Also noteworthy is the absence of any mention in the article of the ethical issues associated with the exploitation of pigs, who are intelligent animals, for the sake of this cutting- edge research and innovative treatment. Prior and ongoing pre-clinical xenotransplantation research has also involved transplanting pig hearts into baboons. And the FDA has stipulated that investigators must keep a large number of primates alive for at least six months after transplanting pig organs as a prerequisite to permitting clinical trials in humans .
Success in xenotransplantation would represent an impressive feat of human ingenuity and technological prowess. However, if transplantation of hearts from genetically modified pigs proves viable—a big if—it would, at best, be a mixed blessing. Patients with end-stage heart disease who are unable to receive a human heart transplant would experience prolonged survival, although they might not fare as well as patients who receive a human heart. All transplant patients must take powerful immunosuppressive drugs for the rest of their lives, and these drugs cause vulnerability to serious infections. Some patients on the transplant list might face the agonizing decision of whether to continue waiting for a human heart, at risk of further deterioration, or opt for a genetically-modified pig heart transplant. If xenotransplantation becomes a validated treatment, it will be very expensive. From a societal perspective, would the investment in research and implementation into clinical practice be cost-worthy?
Bioethicists for the most part have not questioned whether xenotransplantation ought, from an ethical perspective, to be pursued, all things considered. Instead, they have focused on how to regulate, ethically, research and development of this exciting innovation. Regardless of the ethical issues it poses, experimentation with xenotransplantation to address the shortage of human organs for transplantation is proceeding full steam ahead. My aim here is not to argue for rejecting xenotransplantation. Rather, I suggest that science journalists and bioethicists should approach xenotransplantation with a wider lens. Worthy of greater attention are reflection on whether the potential benefits of xenotransplantation are worth the costs, promoting effective measures to prevent chronic diseases that give rise to the need for transplantation, as well as the challenging question of whether the promise of xenotransplantation justifies the harmful treatment of pigs and baboons in pursuit of this innovation.
Franklin G. Miller, PhD, is a Professor of Medical Ethics in Medicine at Weill Cornell Medical College and a Hastings Center fellow and board member.
[PHOTO: University of Maryland Medicine]