Overview of the major clinical trials investigating stem cells-based therapies for diabetes

Stem cell-based therapies are a leading frontier in diabetes treatment, aiming to restore insulin-producing β-cell function beyond symptomatic management. Clinical progress has evolved from donor islet transplantation, such as the Edmonton Protocol, to pluripotent stem cell-derived β-cell replacement. Embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) can differentiate into insulin-producing cells, while mesenchymal stem cells (MSCs) provide immunomodulatory and metabolic support. Landmark trials by ViaCyte, Vertex, and Sernova tested ESCs- and iPSCs-derived progenitors with encapsulation devices and bioengineered niches, yielding insights into safety, differentiation, and immune responses. Vertex's VX-880 program achieved insulin independence, and a 2024 Cell study reported the first functional cure of type 1 diabetes using chemical induced iPSCs (CiPSCs)-derived islets. Encapsulation technologies dominate trials, aiming to shield transplanted cells from rejection without systemic immunosuppression, though fibrosis and vascularization remain obstacles. MSCs therapies across Phase 1-3 trials improved glycemic control and β-cell preservation, underscoring their complementary role. Despite promising outcomes, no clinical stem cell-derived therapy is yet routine, with tumorigenicity, immune rejection, and scalability as key challenges. Future directions focus on gene-edited immune-evasive cells, advanced biomaterials, scalable bioreactors, and harmonized regulation to achieve durable insulin independence and global accessibility.