Cell Therapy in Human and Veterinary Medicine: A One Health Perspective on Historical Evolution and European Regulatory Frameworks

Cell therapy has evolved from early interventions based on living cell transfer to become a complex and heterogeneous field that now includes cell-based advanced therapy products, programmable immunotherapies, and cell-derived acellular products. This narrative review examines the historical, translational, and regulatory development of cell therapy from a One Health perspective, integrating human and veterinary medicine. We discuss key milestones, including transfusion medicine, the stem cell concept, the transplantation of haematopoietic stem cells (HSCs), the expansion of mesenchymal stem/stromal cells (MSCs), the development of induced pluripotent stem cells (iPSCs), and the secretome, including extracellular vesicles (EVs). Rather than following a linear trajectory, we examine overlapping developments in regenerative and immunomodulatory approaches and in cellular immunotherapies, including programmable strategies. We contrast the established regulatory pathways, standardisation, and industrial manufacturing of advanced therapy medicinal products (ATMPs) in human medicine with the more recent and heterogeneous development of veterinary cell-based therapies, particularly in non-industrial settings. Together, these differences illustrate how product definition, manufacturing models, clinical evidence generation and non-industrial use shape the regulatory translation of cell-based and acellular therapies. By linking historical milestones with translational and regulatory differences, this review provides a framework for understanding cell-based and cell-derived therapies across human and veterinary medicine.