Parkinson's Disease Cell Transplantation Therapy: A New Dawn With Pluripotent Stem Cell–Based Therapy

Abstract

Parkinson's disease (PD), a prevalent neurodegenerative disorder, is characterized by progressive loss of dopaminergic neurons in the midbrain. While dopamine replacement therapy effectively manages early symptoms, its long-term use leads to motor complications, highlighting the urgent need for treatments that directly address the underlying pathological changes. Cell transplantation, which aims to replace the lost dopaminergic neurons, has emerged as a promising approach. Early attempts using fetal ventral mesencephalic (fVM) tissue showed proof-of-concept, with some patients experiencing long-term motor improvement. However, these trials have been hampered by inconsistent results, graft-induced dyskinesia (GID), and significant ethical and logistical issues related to tissue supply. These challenges have shifted the focus to pluripotent stem cells (PSCs), including human-induced pluripotent stem cells (iPSCs) and embryonic stem cells (ESCs), which offer a stable, ethically sound, and scalable source of high-quality cells. Recent clinical trials using PSCs suggest a turning point. All reported clinical trials demonstrated the safety and feasibility of this approach. The need for long-term safety and efficacy data, patient stratification, and techniques to improve graft survival are key areas of future research. Nevertheless, recent clinical trial successes suggest that cell transplantation is moving beyond symptomatic relief to become a truly restorative therapy for PD.