Phase 1/2a clinical trial of hESC-derived dopamine progenitors in Parkinson’s disease

Parkinson's disease (PD) has long been considered an appropriate candidate for cell replacement therapy. We generated high-purity dopaminergic progenitors (A9-DPCs) from human embryonic stem cells and evaluated their safety and exploratory efficacy in a single-center, open-label, dose-escalation phase 1/2a trial (NCT05887466) for PD patients. Twelve patients with moderate-to-severe PD received bilateral putamen transplantation of low-dose (3.15 million cells; n = 6) or high-dose (6.30 million cells; n = 6) A9-DPC with immunosuppression. No dose-limiting toxicities or graft-related adverse events were observed. At 12 months, off-medication Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part III scores and Hoehn and Yahr stage improved, with greater motor improvements in the high-dose group. Dopamine transporter positron emission tomography (PET) imaging showed increased posterior putamen uptake with greater uptake in the high-dose group after transplantation, supporting graft survival. These findings indicate that bilateral transplantation of A9-DPC is safe and may improve parkinsonian motor symptoms in patients with PD.