Stem Cell Transplantation for Parkinson's Disease

Overseen By Jeffrey S Schweitzer, MD, PhD

Age: 18+

Sex: Any

Trial Phase: Phase 1

Sponsor: Jeffrey S. Schweitzer, MD, PhD

Must be taking: Levodopa, Dopamine agonists

Must not be taking: Anticoagulants, Immunosuppressants

Disqualifiers: Dementia, Psychosis, Stroke, Cancer, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 3

8 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new treatment for Parkinson's disease using stem cells. Researchers aim to determine the safety of transplanting cells from a participant's own skin into their brain. The trial includes two groups: one receives a lower dose, and the other a higher dose of these special cells. It targets individuals who have had Parkinson's for over five years, experience daily symptoms that respond to medication, and are willing to undergo surgery. As a Phase 1 trial, this research focuses on understanding how the treatment works in people, offering participants the opportunity to be among the first to receive this innovative therapy.

Will I have to stop taking my current medications?

The trial requires that you have a stable regimen of Parkinson's medications, like levodopa and dopamine agonists, for at least 4 weeks before screening. However, if you are taking anticoagulation or antiplatelet agents, you must stop them one week before and two days after surgery.

Is there any evidence suggesting that this treatment is likely to be safe for humans?

Research has shown that cell transplants for Parkinson's disease appear promising in terms of safety. In one study with similar cells, researchers found that the cells survived in the brain and produced dopamine, an important brain chemical. Importantly, they did not form tumors, a major safety concern.

Another study tested these cells in animals and found that they improved movement without causing tumors. These findings are encouraging because they suggest the treatment is likely safe and may help with symptoms.

Since this trial is in the early stages, it primarily focuses on safety. Early trials like this assess how well people tolerate a treatment. Researchers closely monitor for any adverse side effects. So far, studies suggest the treatment is well-tolerated, but more research is needed to confirm this in humans. ^{1 2 3 4 5}

Why are researchers excited about this trial's treatment?

Researchers are excited about autologous dopaminergic cell implantation for Parkinson's disease because it offers a novel approach compared to current treatments like medications and deep brain stimulation. Most existing treatments manage symptoms by altering dopamine levels or electrical activity in the brain. In contrast, this treatment involves implanting the patient's own dopamine-producing cells directly into the putamen, a crucial brain region affected by Parkinson's, aiming to restore natural dopamine production. This cell-based therapy holds promise for not just alleviating symptoms but potentially slowing disease progression, which is a significant leap beyond existing options.

What evidence suggests that this treatment might be an effective treatment for Parkinson's disease?

Research shows that using a person's own cells to create dopamine-producing cells might help treat Parkinson's disease. Previous studies using cells from patients have shown promise in restoring dopamine levels in animals. Dopamine is an important brain chemical often lacking in people with Parkinson's. In this trial, participants will receive either a low or high dose of autologous dopaminergic cells. In previous trials, these lab-grown dopamine cells survived and functioned well after transplantation. Early results are encouraging, suggesting this method could potentially improve symptoms by replacing lost dopamine in the brain. ^{1 6 7 8 9}

Are You a Good Fit for This Trial?

This trial is for individuals with Parkinson's Disease who experience symptoms like tremors and stiffness. Participants will have their own skin cells used to create special nerve cells that are missing in this disease.

Inclusion Criteria

English proficiency sufficient to understand the consent form and participate in a discussion of risks and benefits

I have been diagnosed with Parkinson's Disease.

My Parkinson's is advanced, affecting my movement without medication.

Exclusion Criteria

Pregnant or nursing women

I have had a stroke or a transient ischemic attack.

Subjects with alcohol or drug addiction

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Cell Production

Fibroblast samples are collected from participants to produce autologous midbrain dopaminergic progenitor cells

4-8 weeks

Transplantation

Surgical transplantation of dopaminergic progenitor cells into the putamen under general anesthesia

1 week

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness through clinical assessments and neuroimaging

2 years

Regular visits (in-person and virtual) over 2 years

What Are the Treatments Tested in This Trial?

Interventions

• Autologous Dopaminergic Cell Implantation

Trial Overview The study tests a new procedure where doctors take a person's skin cells, turn them into nerve cells that produce dopamine (which are lacking in Parkinson's), and then put these back into the patient’s brain.

How Is the Trial Designed?

Group I: Low dose administration Experimental Treatment 1 Intervention

4 million autologous dopaminergic cells will be implanted into the putamen on each side of the brain

Group II: High dose administration Experimental Treatment 1 Intervention

8 million autologous dopaminergic cells will be implanted into the putamen on each side of the brain

Who Is Running the Clinical Trial?

Jeffrey S. Schweitzer, MD, PhD

Lead Sponsor

Trials

1

Recruited

8+

Published Research Related to This Trial

In a study using rat models of Parkinson's disease, L-DOPA treatment did not negatively affect the survival or function of human embryonic stem cell-derived dopaminergic neuron grafts, suggesting it is safe to use alongside grafting procedures.

L-DOPA administration led to early improvements in dyskinesia, indicating that the grafts may help manage dopamine levels sooner than expected, which is important for optimizing patient outcomes in future clinical trials.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Human Embryonic Stem Cell-Derived Dopaminergic Grafts Alleviate L-DOPA Induced Dyskinesia. Elabi, OF., Pass, R., Sormonta, I., et al.[2022]

Transplanting dopaminergic neurons derived from human pluripotent stem cells shows potential as a treatment for Parkinson's disease.

Recent studies have identified specific markers for midbrain dopaminergic progenitors, which can enhance the process of deriving these neurons and help predict the amount of dopamine-producing neurons after they are transplanted.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Seq-ing Markers of Midbrain Dopamine Neurons. Osborn, T., Hallett, PJ.[2021]

Stem cell therapy for Parkinson's disease aims to repair damaged neuronal pathways by using either the patient's own neural stem cells or grafted dopaminergic neurons, which can help restore dopamine levels and improve symptoms.

While embryonic stem cells show promise due to their ability to proliferate and differentiate, concerns about tumor formation and ethical issues pose significant challenges for their use in clinical settings.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Stem cell therapy for Parkinson's disease. Takahashi, J.[2007]

Stem-cell-derived transplants are being developed as a potential treatment for Parkinson's disease, with a focus on creating a clinical-grade dopaminergic progenitor cell product.

The study emphasizes the importance of rigorous testing to ensure the safety and efficacy of these stem-cell-derived products before they enter clinical trials.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Embryonic stem cells go from bench to bedside for Parkinson's disease. Parish, CL., Thompson, LH.[2022]

A groundbreaking study demonstrated the successful transplantation of dopamine neurons derived from a patient's own skin cells into a patient with Parkinson's disease, highlighting the potential for personalized cell therapy.

This approach shows promise for autologous transplantation, meaning the patient's own cells are used, which may reduce the risk of rejection and improve treatment outcomes for dopamine cell replacement.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

From Skin to Brain: A Parkinson's Disease Patient Transplanted with His Own Cells. Parmar, M., Björklund, A.[2021]

Over three decades of research into dopamine cell replacement therapy for Parkinson's disease has led to the transplantation of fetal-derived dopamine neuroblasts in 18 patients, with some encouraging results regarding neuron survival and function in the human brain.

The journey has included both significant breakthroughs and setbacks, highlighting the complexity of developing effective treatments for Parkinson's disease and the ongoing advancements in this field.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Replacing Dopamine Neurons in Parkinson's Disease: How did it happen? Björklund, A., Lindvall, O.[2023]

Neurotransplantation for treating Parkinson's disease has been in human trials for over 15 years but faces significant political and scientific challenges that hinder progress.

Recent advancements include the transplantation of new dopaminergic cell lines into a primate model of Parkinson's disease, marking a crucial step in developing stem cell therapies for this condition.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The promise of stem cells in Parkinson disease. Langston, JW.[2018]

The study demonstrated that autologous induced pluripotent stem cell (iPSC)-derived dopamine neurons can improve behavior in a cynomolgus monkey model of Parkinson's disease, indicating potential efficacy for treating the condition.

No immunosuppression was needed for the grafts, and histological analysis showed a significant number of surviving dopamine neurons without any overgrowth, suggesting a safe approach for cell replacement therapy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Autologous iPSC-derived dopamine neuron transplantation in a nonhuman primate Parkinson's disease model. Wang, S., Zou, C., Fu, L., et al.[2020]

Autologous adult neural stem cells (NSCs) present a promising cell therapy option for treating Parkinson's disease by potentially replacing lost dopaminergic neurons, addressing the core issue of dopamine depletion in the striatum.

Using NSCs from adult tissue avoids ethical concerns associated with fetal or embryonic stem cells and allows for personalized treatment through autologous transplantation, where the patient's own cells are used.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Autologous neural stem cell transplantation: a new treatment option for Parkinson's disease? Arias-Carrión, O., Yuan, TF.[2009]

Stem cell-derived dopamine neuron transplantation shows promise as a potential curative therapy for Parkinson's disease, addressing the loss of dopaminergic neurons and aiming to restore dopamine levels in the brain.

Factors such as the source and quality of stem cells, patient age, disease progression stage, surgical techniques, and immunosuppression practices significantly influence the outcomes of cell transplantation, highlighting the need for careful consideration in clinical trials.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Current Status of Stem Cell-Derived Therapies for Parkinson's Disease: From Cell Assessment and Imaging Modalities to Clinical Trials. Jang, SE., Qiu, L., Chan, LL., et al.[2020]

Stem cells can potentially be used to treat Parkinson's disease by generating new dopaminergic neurons through cell replacement therapy, which involves using embryonic stem cells, multipotent stem cells, or neuronal progenitor cells.

Another promising approach is engineering multipotent stem cells to produce glial cell-line derived neurotrophic factor, which supports the survival and growth of dopaminergic neurons, offering a neuroprotective and neuroregenerative strategy for treating the disease.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Stem cells in the treatment of Parkinson's disease. Arenas, E.[2019]

Citations

1. nature.com nature.com/articles/s41586-025-08700-0

Phase I/II trial of iPS-cell-derived dopaminergic cells for ... Pluripotent stem (PS) cells emerged as a promising alternative for developing safe and effective treatments. In this phase I/II trial at Kyoto ...

2. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC4462124/

Successful function of autologous iPSC-derived dopamine ... We analyzed cynomolgus monkey (CM) iPSC-derived midbrain dopamine neurons for up to 2 years following autologous transplantation in a Parkinson's disease (PD) ...

3. clinicaltrials.gov clinicaltrials.gov/study/NCT06687837

NCT06687837 | Treating Parkinson's Disease Through ... This Phase I, open-label clinical trial aims to assess the feasibility and safety of autologous midbrain dopaminergic progenitor cell (mDAP) transplantation for ...

4. sciencedirect.com sciencedirect.com/science/article/pii/S209592732300720X

First-in-human transplantation of autologous induced ... Perspective. First-in-human transplantation of autologous induced neural stem cell-derived dopaminergic precursors to treat Parkinson's disease.

5. nejm.org nejm.org/doi/full/10.1056/NEJMoa1915872

Personalized iPSC-Derived Dopamine Progenitor Cells for ... We report the implantation of patient-derived midbrain dopaminergic progenitor cells, differentiated in vitro from autologous induced pluripotent stem cells ( ...

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC6994130/

Human autologous iPSC–derived dopaminergic progenitors ... Transplantation of these cells into rodent models of PD robustly restores motor function and reinnervates host brain, while showing no evidence of tumor ...

7. nature.com nature.com/articles/s41586-025-08845-y

Phase I trial of hES cell-derived dopaminergic neurons for ... Secondary and exploratory clinical outcomes showed improvement or stability, including improvement in the Movement Disorder Society Unified ...

8. clinicaltrials.gov clinicaltrials.gov/study/NCT06687837

NCT06687837 | Treating Parkinson's Disease Through ... This Phase I, open-label clinical trial aims to assess the feasibility and safety of autologous midbrain dopaminergic progenitor cell (mDAP) transplantation ...

9. sciencedirect.com sciencedirect.com/science/article/abs/pii/S1934590925000062

Pre-clinical safety and efficacy of human induced ... Pre-clinical safety and efficacy of human induced pluripotent stem cell-derived products for autologous cell therapy in Parkinson's disease.