Safety and Feasibility of Bilateral Striatal Transplantation of DopaCell in Parkinson's Disease

Evaluation of the Safety and Feasibility of a Single Transplantation of 10 Million Human Embryonic Stem Cell-Derived Dopaminergic Progenitor Cells Into the Bilateral Striatum of Patients With Moderately Severe Parkinson's Disease: a Multicenter, Open-label, Single-arm Phase I Clinical Trial

Dopason is a phase I, open-label, multicenter, single-arm clinical trial designed to evaluate the safety and feasibility of intraputaminal transplantation of human embryonic stem cell-derived dopaminergic progenitor cells (DopaCells) in patients with moderately severe Parkinson's disease.

Study Overview

• Status: Recruiting
• Conditions: Parkinson Disease (PD)
• Intervention / Treatment: Biological: Dopacell; Drug: Immunosuppressive Regimen; Device: Customized microinjection device

Detailed Description

During this trial phase, a total of ten participants will be included and distributed between two clinical centers. Each participant will undergo one standardized surgical procedure consisting of bilateral stereotactic intraputaminal transplantation of approximately 10 × 10⁶ cells in total (about 5 × 10⁶ cells per putamen), aiming to achieve an estimated survival of 200,000 neurons. All procedures will be performed using the same surgical delivery system and an almost identical operative protocol across both sites to ensure procedural consistency. After transplantation, patients will receive immunosuppressive therapy for a duration of one year and will be systematically followed for study outcomes for at least 12 months.

• Study Type: Interventional
• Enrollment (Estimated): 10
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Sarvenaz Salahi, MD; Phone Number: 021-23562000; Email: salahi13639@gmail.com

Study Locations

• Iran
  • Tehran, Iran
    • Recruiting
    • Royan Institute
    • Contact: Sarvenaz Salahi, PhD; Phone Number: 021-2356200; Email: salahi13639@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age: 30-70 years
• Diagnosis of PD: MDS clinical Diagnostic Criteria for Parkinson's disease
• The disease duration more than 5 years
• Moderate Parkinson's disease, defined as a Hoehn and Yahr stage of 2 or 3 during the OFF period.
• The patient is receiving oral pharmacological therapy, and in the opinion of the Principal Investigator, the patient's symptoms remain inadequately controlled despite optimal medical management, or the patient is experiencing adverse effects related to their current treatment
• No history or only mild levodopa-induced dyskinesia, defined as a score of 2 or less on the UDysRS scale in any body region during the ON state.
• The patient demonstrates a clinically meaningful response to a therapeutic dose of levodopa, as determined by the Principal Clinical Investigator or a trained specialist under the supervision of the Principal Investigator.

• The performance of different organs based on laboratory evaluations:

  • Number of neutrophils ≥2000 / microliter
  • Platelet count ≥100,000 / microliter
  • AST / ALT: less than or equal to three times the maximum normal value at the intervention site
  • Total bilirubin less than or equal to 1.5 times the maximum normal amount at the intervention site
  • eGFR * rate: greater than or equal to 60 ml / min / 1.73 m2 * eGFR (mL / min / 1.73 m2) = 194 X Cr ^ -1.094 X age ^ -0.287 (X 0.739 for females)
• Informed consent

Exclusion Criteria:

• The abnormal function of immune system
• The symptomatic brain injuries (brain atrophy, cerebral Infarct, trauma, vascular malformation) confirmed by brain MRI
• Markedly reduced or normal signal in the ventral striatum on TRO-DaT SPECT imaging.
• Any abnormal findings on brain MRI.
• Positive GBA mutation test.
• Diagnosis of dementia based on a MoCA score < 24.
• The abnormality of thrombotic system or high risk of bleeding
• Positive for any of the following viral markers or active infections: HBsAg, HBsAb, HBcAb, anti-HIV antibodies, anti-HTLV-1&2 antibodies, active hepatitis C infection, syphilis, or active CMV, VZV, EBV, or COVID-19 infection.
• Impossibility of MRI imaging for patients with metal in the body, pacemaker in the body, claustrophobia, with artificial heart valves that are incompatible with MRI or body weight is not within the tolerable range for MRI.
• Patients with contraindications to the study drug: Tacrolimus, Prednisolone, Basiliximab, Cotrimoxazole, MRI contrast agent.
• Patients undergoing other cell transplants, including embryonic stem cell-derived dopaminergic progenitor cells.
• Patients with a history of PD at the same time and concurrent: Malignant neoplasm, epilepsy, cerebral hemorrhage or a positive history
• Psychiatric disorders confirmed by a psychiatrist, including major depression, bipolar disorder, or schizophrenia, that are uncontrolled or treatment resistant.
• Patients with intellectual disability who, in the judgment of a psychiatrist, are unable to fully comprehend the study requirements.
• History of pallidotomy, thalamotomy, or deep brain stimulation (DBS).
• Patients considered high-risk candidates for surgery, particularly neurosurgery or DBS implantation, due to significant cardiovascular, pulmonary, or other systemic comorbidities identified during preoperative evaluation.
• Patients who have a history of taking the following in the three months prior to enrollment: Immunosuppressant, antipsychotic drug, anticonvulsant drugs or anticoagulant therapy (if discontinuation or perioperative adjustment is not feasible), botulinum toxin (within 6 months), phenol injections, or other treatments for dystonia or muscle spasm
• History of Apomorphine use
• History of chronic alcohol use or illicit drug abuse.
• Patients who are pregnant, lactating, or people who did not avoid pregnancy during the study.
• Patients who, according to the researchers' opinions, are not suitable for safe study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Transplantation; Experimental: DopaCell Biological: DopaCell, 5 million cells per putamen Immunosuppressive Regimen: Basiliximab, Tacrolimus, Prednisolone Device: Customized microinjection device	Biological: Dopacell; DopaCells are dopamine-producing progenitor cells generated from human embryonic stem cells through differentiation under GMP-compliant conditions.; Drug: Immunosuppressive Regimen; Basiliximab, Tacrolimus, Prednisolone; Device: Customized microinjection device; For intraputaminal delivery of DopaCell

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Safety	Incidence and severity of treatment-emergent adverse events (TEAEs)	Baseline to 12 Months Post-Transplant
Safety	Evidence of any post-transplantation anatomical changes at the transplant site suggestive of tumor formation, as assessed by MRI imaging.	Baseline to 12 Months Post-Transplant
Feasibility	Successful completion of a single-session intraputaminal transplantation with of the intended cell dose	Baseline to 12 Months Post-Transplant

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Efficacy	Changes in the duration of OFF and ON periods following intracerebral DopaCells transplantation as assessed by the Hauser diary	Baseline to 12 Months Post-Transplant
Efficacy	Changes in the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part III score from baseline following intracerebral DopaCells transplantation during ON and OFF periods ( MDS-UPDRS Part III ranges from 0 to 132, where higher scores indicate worse motor impairment.)	Baseline to 12 Months Post-Transplant
Efficacy	Graft survival following intracerebral DopaCells transplantation based on TRODAT SPECT imaging findings.	Baseline to 12 Months Post-Transplant
Continuous Safety	Continuous Safety: The number and severity of treatment-emergent adverse events	Baseline to 60 Months Post-Transplant

Collaborators and Investigators

• Sponsor: Royan Institute
• Collaborators: Shiraz University of Medical Sciences; Iran University of Medical Sciences; Royan AtiTech Pharmed

Study record dates

Study Major Dates

• Study Start (Actual): August 1, 2025
• Primary Completion (Estimated): August 1, 2028
• Study Completion (Estimated): August 1, 2030

Study Registration Dates

• First Submitted: April 7, 2026
• First Submitted That Met QC Criteria: May 2, 2026
• First Posted (Actual): May 7, 2026

Study Record Updates

• Last Update Posted (Actual): May 7, 2026
• Last Update Submitted That Met QC Criteria: May 2, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Parkinson's disease; Dopaminergic progenitor cell transplantation; Intrastriatal
• Additional Relevant MeSH Terms: Synucleinopathies; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Neurodegenerative Diseases; Movement Disorders; Parkinsonian Disorders; Basal Ganglia Diseases; Parkinson Disease
• Other Study ID Numbers: 402000063

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No