Current status of pancreatic islet xenotransplantation

Pancreatic islet transplantation represents the optimal treatment for severe hypoglycemia, a serious complication experienced by patients with long-term type 1 diabetes who are undergoing insulin therapy. However, the limited availability of donor organs restricts its widespread use. Porcine pancreatic islets could offer a viable alternative to address this organ shortage. For successful pancreatic islet xenotransplantation using porcine pancreatic islets, efficacy and safety must first be demonstrated in pig-to-nonhuman primate (NHP) preclinical studies, as outlined in the consensus statement of the International Xenotransplantation Association. Our group has achieved long-term survival of wild-type porcine islet grafts in immunosuppressed NHPs by employing two immunosuppressive protocols: one based on CD40-CD40L blockade and another utilizing clinically available immunosuppressants. A clinical trial for pancreatic islet xenotransplantation, following the latter protocol, has received approval from the Korean Ministry of Food and Drug Safety (MFDS). This review aims to highlight the results of clinical trials involving porcine islet xenotransplantation to date, along with the age-specific and other characteristics of the porcine islets used in these trials and the preclinical NHP studies that support them. It offers insights into the perspectives around the first clinical islet xenotransplantation approved by the Korean MFDS, emphasizing improved long-term graft survival.