Abstract
The field of regenerative medicine for Parkinson's disease (PD) has reached a pivotal moment. After decades of preclinical research, recent first-in-human clinical trials demonstrated that cell replacement therapy using stem cell-derived dopaminergic neurons is not only feasible and safe but also shows promising signs of efficacy. Here we analyze three landmark 2025 studies, including the phase I/II trial of allogeneic induced pluripotent stem cell-derived dopaminergic progenitors, that mark a significant leap forward for PD therapy. We discuss principles underpinning the therapy, the historical context of fetal tissue transplants, findings from recent trials, and critical challenges. The convergence of robust cell manufacturing, precise stereotactic surgery, and advanced neuroimaging provides compelling evidence that stem cell-based therapies are potentially a viable treatment paradigm for PD.