Stem Cell Research Parkinson's

Research looking into how Stem Cells could help people with Parkinson’s has been ramping up over the past few years. Here’s a look at what we know so far from the studies that have been done in humans post 2020. There’s a lot to go through here! If it’s tough to digest, scroll down to our conclusion where we’ve summarized it all for you.

If you want to know more about the treatment process for Parkinson’s, our article here goes into more depth. Or set up a conversation with our team here. They can guide you in deciding if it’s the right fit, help you choose the best clinic & region, and even assist you in securing some great discounts!

Current Trials (2025)

Kyoto Hospital IPSC Trial (Japan)

(You can read the full study here)

Who’s Running It:

The trial is being conducted at Kyoto University Hospital in Japan. It’s the first human trial to use stem cells made from a healthy donor’s skin to try and replace lost dopamine-producing brain cells in people with Parkinson’s disease.

Participants:

7 adults between 50 and 69 years old who had mid-stage Parkinson’s disease.

All participants were on stable medication but still had motor symptoms.

What They’re Testing:

This study is testing whether dopamine-producing brain cells grown from stem cells can safely be transplanted into the brain and help improve movement problems caused by Parkinson’s.

The cells came from induced pluripotent stem cells (iPSCs), which are created by turning back the clock on adult skin cells to make them behave like embryonic stem cells.

These iPSCs were then guided in the lab to become dopaminergic progenitor cells. The kind that make dopamine, which is lost in Parkinson’s.

The cells were transplanted directly into a part of the brain called the putamen, which is responsible for movement.

Cell Count:

Participants received the cells surgically in both sides of the brain, with two different dose groups:

Low Dose Group: 2.4 million cells per side (4.8 million total)

High Dose Group: 4.8 million cells per side (9.6 million total)

How the Stem Cells Were Made:

The iPSCs came from skin cells donated by a healthy adult with a common immune type, making them more likely to be accepted by different patients.

The donor’s skin cells were reprogrammed using a non-viral method (episomal plasmids). A safer process that doesn’t alter DNA permanently.

Key genes like OCT4, SOX2, KLF4, L-MYC, and LIN28 were used to reverse the cells back into a stem-like state.

Tumor Testing & Safety Checks:

Before being used in humans, the cells were:

Scanned for mutations and tested for genetic stability
Injected into lab animals to check for tumor formation over 12 months

Monitored in patients for 2 years after transplant. No tumors, no overgrowth, and no serious side effects were found in any of the 7 participants.

What They’re Measuring:

Primary Outcome:

Safety: any adverse events (no serious ones occurred)

Secondary Outcomes:

Changes in movement symptoms using a standard Parkinson’s scale (UPDRS-III)

Brain dopamine activity using PET scans

Overall daily functioning

Results So Far:

5 out of 6 patients showed improvement in movement when on medication, and 4 improved even off medication.

PET scans showed a 44.7% increase in dopamine activity in the brain’s motor areas, especially in those who got the higher dose.

Timeline:

Start Date: 2018

Follow-up Completed: 2022

Why It Matters:

It proved that the approach is safe and may help restore lost brain function.

The increase in dopamine activity is a strong signal that the transplanted cells survived and worked.

What’s Next:

A larger, placebo-controlled trial is being planned.

It will:

Include more patients to confirm the benefits

Use the higher dose, which showed the best results

Possibly adjust immunosuppressants or focus on earlier-stage patients

Take place mainly in Japan but may expand internationally

This next trial will be critical to prove whether stem cell therapy can truly change the course of Parkinson’s disease. Not just treat symptoms but replace the lost brain cells.

UniXell UX-DA001 Trial: Autologous IPSC Cells (China)

(You can read more about the study here)

Who’s Running It:
UniXell Biotechnology, in partnership with Ruijin Hospital in Shanghai. The trial is led by Dr. Jun Liu (Neurology) and Dr. Li Dianyou (Neurosurgery).

Participants

Adults aged 50–75 years with 5–15 years of Parkinson’s.
Participants must still respond to levodopa but are experiencing declining benefit from medication.
Participants must be in Stage 3 or 4 of the disease (on the Hoehn-Yahr scale) and have no serious infections, cancers, or brain abnormalities.

What They’re Testing:
A personalized stem cell therapy called UX-DA001, designed to help people with idiopathic Parkinson’s disease (the most common type). The goal is to see if this one-time treatment can safely improve motor symptoms like tremors, stiffness, and movement slowness.

What Makes This Treatment Different?

The Cells Come from the Patient
Scientists take a small blood sample from each participant. They reprogram those blood cells into induced pluripotent stem cells (iPSCs)
Programming the Cells
These iPSCs are then carefully guided in the lab to become dopamine-producing brain cells, the exact type that die off in Parkinson’s. These lab-grown neurons are called midbrain dopaminergic progenitor cells.
Why That Matters
Since the therapy uses the patient’s own cells, there’s no need for immunosuppressive drugs. That reduces the risk of side effects like infections, tumors, or organ damage

How It’s Delivered

Each patient gets a single dose of UX-DA001. The cells are implanted into both sides of the brain (the putamen, a key area for movement control) using stereotactic neurosurgery. A precise, minimally invasive brain surgery done under general anesthesia.

What Are They Measuring?

The researchers are looking at both safety and effectiveness over 2 full years. Here’s what they’re tracking:

Primary Measures (Safety):

Adverse events within the first 4 weeks and throughout the 2-year period.
Monitoring for serious complications related to the surgery or the implanted cells.

Secondary Measures (Efficacy):

Brain scans (PET and MRI) to check if the cells survive, grow appropriately, and don’t form tumors.
Changes in:
- Motor function scores (UPDRS Part II & III)
- Daily medication needs (levodopa dose)
- Non-motor symptoms like sleep and mood
- Overall disease stage (Hoehn-Yahr scale)

What They Found:

The first patient showed improvements in both sleep quality and motor function just one month after surgery, with no serious adverse events reported.

The patient described a gradual, day-by-day improvement in symptoms.

While these early results are promising, the trial is still ongoing and designed to follow patients for up to two years to fully evaluate long-term safety and effectiveness.

What Makes This Trial Important?

This is China’s first registration-directed clinical trial for a personalized iPSC-derived Parkinson’s treatment. And it’s one of the few globally that:

Uses autologous (self-derived) cells
Avoids immunosuppressants
Has regulatory approvals from both China’s NMPA and the U.S. FDA

If it’s successful, it could signal a major shift from daily drug management toward long-lasting, personalized cell therapy. Restoring dopamine function instead of just managing symptoms.

iCamuno IPSC-DAP Trial (China)

(You can view the clinical trial listing here)

Who’s Running It:
The trial is run by iCamuno Biotherapeutics, a biotech company focused on cell therapies. It’s being carried out at the Second Affiliated Hospital of Zhejiang University School of Medicine in China.

Participants:

12 adults between 39 and 75 years old with advanced Parkinson’s disease.

All participants had been living with Parkinson’s for more than 5 years.
They were taking levodopa, but still had issues like “off” periods (when the medicine stops working) or involuntary movements (dyskinesia).

What They’re Testing:

The trial is testing whether new dopamine-producing brain cells made from a patient’s own blood or skin can safely be placed into the brain to help improve movement and reduce the need for medication.

These new brain cells are made using iPSCs. That’s a method where regular adult cells, like skin or blood are turned back into a stem cell state. These iPSCs can then be guided to become any type of cell in the body. In this case, they’re turned into dopamine progenitor cells. Early-stage brain cells that can grow into the kind that make dopamine, the chemical that helps control movement and is lost in Parkinson’s.

The new cells are injected directly into an area of the brain called the putamen. That’s a part of the brain that helps control movement and is especially affected in Parkinson’s disease.

Cell Count:

Each participant will receive 4 million cells on each side of the brain. That’s a total of 8 million dopamine-making cells.

How the Stem Cells Were Made:
The process starts with a small sample of either skin or blood from the patient.

These cells are reprogrammed into iPSCs using iCamuno’s special method, called iCam-iPSC. This method is designed to create high-quality stem cells that are more stable and safer to use.
These stem cells behave more like natural embryonic stem cells. But since they come from the patient’s own body, they don’t raise the same ethical concerns and are less likely to be rejected by the immune system.

Once the iPSCs are created, they are guided in the lab to become dopamine-producing brain cells.

iCamuno uses artificial intelligence and advanced testing tools to improve the process and make sure the cells are healthy, consistent, and ready for use in patients.

Tumor Testing & Safety Checks:
Before any cells are used in surgery, they go through several safety checks:

The lab checks the cells for harmful mutations or genetic problems
Toxicity tests are done to make sure the cells don’t cause damage
PET and MRI scans are used to check the brain before and after treatment
After surgery, patients are monitored closely for a full year to check for side effects or problems with the cells

What They’re Measuring:
Primary Outcome:
Safety: looking at whether there are any serious side effects or complications from the treatment

Secondary Outcomes:

Changes in motor symptoms using a standard Parkinson’s rating scale (UPDRS-III)
Changes in Parkinson’s stage using the Hoehn and Yahr scale
Changes in quality of life using a questionnaire called PDQ-39
How much Parkinson’s medication the person needs after the treatment
Changes in brain dopamine activity, measured with a special PET scan (18F-DAT)

Timeline:
Start Date: May 2025
Initial Results: December 2025
Full Study Completion: September 2026

Nuwacell NCR201 iPSC Trial (China)

(You can read more on this trial here)

Who’s Running It:
The trial is being run by Nuwacell Biotechnologies in China. It’s a Phase 1 study looking at whether dopamine-producing brain cells made from donor stem cells can be safely implanted into people with Parkinson’s disease.

Participants:

48 adults between 40 and 75 years old with Parkinson’s disease lasting more than 5 years.
All participants must be on a stable dose of dopamine-based medication and able to undergo brain imaging.

What They’re Testing:

The study is testing whether special brain cells grown in a lab can help improve symptoms of Parkinson’s disease, like shaking, muscle stiffness, and slow movement.

These brain cells are called dopaminergic progenitor cells. They’re the kind that make dopamine, a chemical that helps control movement and is missing in people with Parkinson’s.

The cells come from induced pluripotent stem cells (iPSCs). These are created by taking blood cells from a healthy donor and turning them back into stem cells. Scientists then guide those stem cells to become the dopamine-producing type.
Once the cells are ready, they’ll be carefully implanted into a part of the brain called the putamen. An area that helps control movement. The cells will be placed on both sides of the brain using a precise surgical method.
The idea is to make a ready-to-use treatment (called “off-the-shelf”) that doesn’t need to be custom-made for each patient.

Cell Count:
The study includes two groups:

Low Dose Group: exact dose not disclosed
High Dose Group: exact dose not disclosed

How the Stem Cells Were Made:

The stem cells used in this trial are called iPSCs, or induced pluripotent stem cells. They were made from blood cells donated by a healthy adult.

Scientists used a special method called episomal reprogramming to turn these blood cells into stem cells. This method doesn’t use viruses and doesn’t change the cells’ DNA permanently, which makes it safer.

Once the stem cells were made, they were grown and carefully selected in the lab. Over several months, the team guided them to become dopaminergic progenitor cells. The kind that can make dopamine, the brain chemical that’s lost in Parkinson’s disease.

Nuwacell says the final cells are “transgene-free,” meaning they don’t contain extra foreign genes, and that they can produce consistent batches of cells for treatment.

What They’re Measuring:

Primary Outcome:

Safety: any adverse events within 24 weeks of transplantation

Secondary Outcomes (over 24 months):

Changes in movement symptoms, like shaking, balance, and how well someone can move

Overall quality of life, including how Parkinson’s affects daily activities

Levels of depression and anxiety

How far the disease has progressed

Brain scans to see if the transplanted cells are still alive

Whether patients need more or less Parkinson’s medication after treatment

Results So Far:
The trial is not yet recruiting. No results have been posted.

Timeline:
Start Date (Estimated): May 31, 2025
Primary Completion: July 1, 2026
Full Study Completion: December 1, 2028

TED-A9 HeSC Trial by S.BIOMEDICS (South Korea)

(You can read more about the study here and press release here)

Who’s Running It:

This clinical trial was led by Professor Dong-Wook Kim from Yonsei University College of Medicine and conducted by the biotechnology company S.BIOMEDICS in South Korea.

Participants:

12 adults aged between 50 and 75 years who have had Parkinson’s disease for at least 5 years.
All participants were still experiencing movement problems despite using standard Parkinson’s medications.

What They’re Testing:

This study tested whether programmed Human embryonic stem cells could safely improve symptoms of Parkinson’s disease.
Parkinson’s is caused by a loss of dopamine-producing brain cells
TED-A9 therapy aims to replace these lost cells using lab-grown cells that can turn into dopamine-producing neurons once transplanted.
These cells were surgically placed directly into a part of the brain called the putamen, which helps control movement.

Cell Count: Participants were divided into two groups:

Low Dose Group: Received 3.15 million cells total.
High Dose Group: Received 6.30 million cells total.

How the Stem Cells Were Made:

TED-A9 cells were originally grown from human embryonic stem cells (hESCs). Scientists carefully guided these cells using specific chemicals (small molecules) to become the exact type of cells needed: dopamine-producing progenitor cells.
This approach does not involve changing the genes and ensures the cells are safe, consistent, and effective

Cell Quality Checks:

Before transplantation, researchers tested the TED-A9 cells to ensure they functioned correctly.
They confirmed that the cells could produce dopamine, the crucial chemical missing in Parkinson’s patients, by checking dopamine levels under different conditions in the lab. All tests showed the cells were actively producing dopamine.

Tumor Testing, & Safety Checks:

Patients were closely monitored through regular brain scans (MRI and PET) to watch for tumors or abnormal cell growth.
Participants also received frequent medical check-ups, lab tests, and monitoring for any side effects.
So far, the trial has found no tumors or serious health problems directly linked to the treatment.

What They’re Measuring:

Main Goal: Safety, checking for side effects like tumor growth, infection, or bleeding.
Other Goals:
- Improvement in movement symptoms measured by special Parkinson’s disease scales.
- Cognitive improvements (memory and thinking skills).
- Overall quality of life improvements.
- Brain imaging to verify if transplanted cells survive and function properly.

Results So Far (12 months):

Patients who received the higher dose of cells showed notable improvement (44.4%) in movement and daily function, while the lower dose showed a smaller improvement (19.4%).
Brain scans confirmed that transplanted cells were active and producing dopamine.
Patients experienced significant improvements in difficult Parkinson’s symptoms like freezing of movement and medication wearing-off, especially in the high-dose group.
Improvements were also observed in non-movement symptoms and overall daily living activities.

Timeline:

First patient treated: February 2024.
First results reported after 12 months (2024).
Follow-up continues for safety checks up to 5 years after the transplant.

Why It Matters:

TED-A9 therapy is an innovative treatment that could potentially replace lost dopamine cells, significantly improving quality of life for Parkinson’s patients.
This approach could offer a more consistent, reliable treatment compared to previous methods using fetal tissues.
Initial results strongly suggest this could be a breakthrough for Parkinson’s treatment.

What’s Next:

Researchers will continue to track these patients over the next year and beyond to confirm long-term safety and effectiveness.
Plans are in place for larger clinical trials involving more patients to further validate the promising early results and confirm the potential benefits of TED-A9.

Aspiro iPSC Study: ANPD001 (US)

(you can read more about the study here)

Who’s Running It?

This trial is led by Aspen Neuroscience, with clinical sites at UCSF, Banner University, and others across the U.S. It’s part of a first-of-its-kind effort to treat Parkinson’s by replacing damaged brain cells using a patient’s own reprogrammed cells.

This approach is very similar to what researchers in Kyoto did, but with one key twist:

Aspen uses the patient’s own cells, while Kyoto used donor cells.

Who’s Taking Part?

Adults aged 50 to 70 with moderate-to-advanced Parkinson’s disease.
To qualify, participants must still respond well to Parkinson’s medications like levodopa and be healthy enough for minor surgery.

What Are They Testing?

Here’s how it works:

Doctors take a small skin sample from behind the ear or arm.
In the lab, those skin cells are turned into induced pluripotent stem cells.
The stem cells are then converted into early-stage dopamine-producing brain cells. The exact kind that die off in Parkinson’s.
These new cells are surgically implanted into the putamen, a key part of the brain that controls movement.

Do We Know How They Make the Cells?

We know Aspen reprograms skin cells into stem cells, and then into dopamine-producing brain cells.
But we don’t know the exact method they use.

What About Tumor Risk or Safety Checks?

Aspen says they run genetic and quality control tests at every stage using AI-based analysis. That likely includes scanning for mutations or problems during cell development.

How Many Cells Do They Use?

That detail hasn’t been disclosed.

What Are They Measuring?

The main goal right now is safety. Does the treatment cause any problems?

They’re also tracking:

How much “OFF time” is reduced (when meds stop working)
How much “ON time” improves (when symptoms are controlled)

Daily movement, mood, and quality of life

What Have They Seen So Far?

In the first 3 patients (at their 6-month follow-up):

No serious side effects were reported
Minor issues like incision site pain and tongue swelling occurred
Patients saw:
- 45% average improvement in motor symptoms during OFF periods
- 71% improvement in daily living tasks
- About 2 fewer hours of OFF time per day
- About 1.5 more hours of ON time each day

Timeline

Trial Start: 2024
Status: Ongoing. Aspen is still enrolling patients at multiple U.S. sites

Why It Matters

This is the first multi-site trial in the U.S. to use a person’s own reprogrammed cells to try and restore lost dopamine neurons in Parkinson’s disease.
If it works, it could be a whole new way to treat the disease. Not just manage symptoms, but potentially replace the brain cells that Parkinson’s destroys.

Memorial Sloan Kettering & BlueRock Bemdaneprocel (HeSC) Trial (USA & Canada)

(Read the full study here)

Who’s Running It:

This trial was led by doctors and scientists at Memorial Sloan Kettering Cancer Center in New York and the University of Toronto, with support from a biotech company called BlueRock Therapeutics.

They tested a new treatment made from human embryonic stem cells that were turned into brain cells that make dopamine. The chemical that’s missing in people with Parkinson’s disease.

Participants:

12 people with Parkinson’s disease took part:

Most were in their mid-to-late 60s
They had been diagnosed for about 9 years
All were still dealing with movement problems, even while taking medication

What They’re Testing

Doctors are trying to see if they can safely transplant lab-grown dopamine-making brain cells into the part of the brain that controls movement (called the putamen) and help improve Parkinson’s symptoms.

These new cells were designed to replace the ones lost because of Parkinson’s, and possibly help the brain function more normally again.

Cell Dose (How Many Were Given):

Each patient had surgery to place the cells into both sides of their brain. There were two different dose groups:

Low Dose: 0.9 million cells per side (1.8 million total)

High Dose: 2.7 million cells per side (5.4 million total)

How the Cells Were Made:

The cells were created in a lab from human embryonic stem cells using a carefully controlled process to turn them into dopamine-producing cells, the type lost in Parkinson’s. These are NOT IPSC cells.

They were frozen and stored, so they could be used anytime. Like a ready-made medicine.

Before being used in people, the cells were tested for safety, checked to make sure they wouldn’t form tumors, and screened to remove any unwanted types of cells that might cause side effects.

Tumor Testing & Safety Checks:

To make sure the cells were safe:

They were tested in animals to rule out tumor growth
They were carefully screened to ensure they wouldn’t become any other type of cell
After surgery, all patients were closely monitored with brain scans and checkups

What they found:

No tumors
No abnormal tissue growth
No dangerous side effects caused by the cells

What They’re Measuring:

Main Goal:

Safety: Were there any serious side effects from the surgery, the cells, or the immune-suppressing drugs?
→ No major issues were found.

Other Goals:

Did the transplanted cells survive and work?
→ Yes — brain scans showed increased dopamine activity where the cells were placed.
Did the patients’ movement problems get better?
→ Yes — especially in the high-dose group.
Did it reduce the amount of time they had symptoms each day?
→ Yes — by about 2.7 hours per day in the high-dose group.
Did they need more medication?
→ No — medication use stayed about the same or decreased slightly.

Were there any involuntary movements (called dyskinesias) caused by the graft?
→ No and that’s a big deal. Previous stem cell trials had problems with this.

Results So Far:

Everyone completed at least 18 months of follow-up
People in the high-dose group improved the most, with a 23-point improvement on a standard Parkinson’s motor scale (that’s considered a major improvement)
Brain scans showed the new cells survived and were making dopamine

No one developed graft-related movement problems (a major issue in older types of cell therapy)

Timeline:

Trial Start: Enrollments began in 2021
Results Published: May 2025

Long-Term Follow-Up: Ongoing through 2027

Why It Matters:

This is the first time a ready-to-use, lab-made dopamine cell product from embryonic stem cells was safely used in humans.

It avoided the ethical and technical problems of using fetal brain tissue
It showed early signs that the cells can survive, function, and improve movement

It could become a scalable therapy for Parkinson’s. Something that can be made in large batches and used when needed

What’s Next:

Based on the positive results, the same therapy (bemdaneprocel) is now moving into a larger Phase III clinical trial called exPDite-2.

Led by BlueRock Therapeutics (a Bayer subsidiary), this will be the first-ever registrational Phase III trial of an off-the-shelf, embryonic stem cell derived therapy for Parkinson’s.

The study will enroll around 100 participants, include a placebo (sham surgery) control group, and measure motor function, quality of life, and safety over 78 weeks.

It’s expected to begin in the first half of 2025. They announced their press release here.

Longeveron Laromestrocel Phase 2/3 Trial (Allogenic MSC): US

(you can read the full study here)

Who’s Running It:
This trial was conducted by doctors and researchers from several well-known medical centers in South Florida, including Longeveron, the University of Miami, and specialized Alzheimer’s research clinics. It was supported by Longeveron, a company that develops new therapies using special stem cells.

Participants:

49 people with early-stage Alzheimer’s disease participated.
The average participant age was around 74.
Most were women
They all had mild Alzheimer’s symptoms and were receiving typical Alzheimer’s medications.

What They’re Testing:

Researchers tested whether giving human derived allogeneic mesenchymal stem cells could safely help slow Alzheimer’s disease.

These mesenchymal stem cells came from healthy donors and could potentially help reduce inflammation and damage in the brain, common issues in Alzheimer’s.
The scientists expected these cells to naturally find inflamed or damaged areas in the brain and release healing signals. These signals could reduce inflammation and support brain health, rather than turning into new brain cells themselves.

Cell Dose (How Many Were Given):
Participants were split into four groups:

A placebo group received only a harmless solution without cells.
A single low-dose group received 25 million stem cells once.
A repeated low-dose group received 25 million cells each month for four months.

A repeated high-dose group received 100 million cells each month for four months.

Tumor Testing & Safety Checks:
To ensure safety:

Cells were carefully screened and tested to ensure they were safe and pure.
Scientists confirmed no harmful viruses or unwanted cells were present.
Earlier animal tests showed they did not cause tumors.
No special drugs were needed to suppress the immune system before treatment.
Patients were monitored closely with regular checkups, blood tests, and MRI brain scans.

What They Found:

No tumors or harmful growths occurred.
No serious or harmful side effects were linked to the treatment.

Any minor side effects were minimal and not directly related to the stem cells.

What They’re Measuring:

Main Goal (Safety): Were there any serious health problems from the treatment?
→ The treatment was found to be very safe, with no major issues.
Other Goals:
- Did the stem cells help protect the brain from shrinking and inflammation?
  → Yes, brain scans showed less brain shrinkage and inflammation.
- Did patients experience improvements in memory, thinking, and daily tasks?
  → Yes, tests showed noticeable improvement, especially in groups receiving multiple doses.
- Did the treatment enhance quality of life?
  → Yes, especially in the higher-dose groups.

Results So Far:

All patients completed nearly 10 months of follow-up.
Patients who received repeated doses of stem cells showed significant slowing in Alzheimer’s disease progression compared to those who didn’t.
Brain scans showed better preservation of brain size, particularly in the hippocampus a key area for memory.

Participants who received higher doses saw the most benefit

Timeline:

Trial Start: Participants joined starting in December 2021.

Results Published: March 2025.

Why It Matters:

This trial showed that stem cells from healthy donors could be safely given through an IV to Alzheimer’s patients.
Unlike traditional treatments, these stem cells target inflammation and blood vessel health in the brain, offering a potentially new way to treat Alzheimer’s.
The safety and simplicity of the treatment (no immune-suppressing drugs needed) make it promising for widespread use.

What’s Next:

Because of these promising early results, Longeveron is planning a larger, pivotal Phase 2/3 clinical trial to confirm these benefits.

This important trial is expected to start in the second half of 2026 and, if successful, will pave the way for FDA approval.

The FDA has given laromestrocel special designations (RMAT and Fast Track) to speed up the review and approval process.

The upcoming study will include more participants, a longer follow-up period, and detailed measurements to fully assess the therapy’s effectiveness in treating mild Alzheimer’s disease.

Longeveron’s Press release is here.

Mass General Brigham Autologous iPSC Trial (USA)

(You can read more about the study here)

Who’s Running It:
This Phase 1 trial is being run by Brigham and Women’s Hospital in Boston, part of the Mass General Brigham system. The treatment was developed by the Neuroregeneration Research Institute (NRI) at McLean Hospital, based on over 30 years of research led by Dr. Ole Isacson.

Participants:
The trial plans to include 6 participants diagnosed with Parkinson’s disease. As of March 2025, 3 of the 6 patients had received the treatment.

What They’re Testing:

The study is testing whether a patient’s own blood cells can be used to create stem cell-derived dopamine neurons that replace the ones lost in Parkinson’s disease.

Blood cells are collected from each patient and converted into induced pluripotent stem cells (iPSCs). These are then turned into midbrain dopaminergic neurons in the lab.

The final product is surgically implanted into the brain’s putamen region, where dopamine neurons normally reside. The goal is to test whether these new neurons can survive, integrate, and restore dopamine function.

Cell Count:
Not disclosed.

How the Stem Cells Were Made:

The stem cells are autologous, meaning they come from the patient’s own blood.
These blood cells are reprogrammed into iPSCs and then differentiated into dopaminergic neurons using a protocol developed by the NRI at McLean Hospital.

The technique avoids donor cells and immunosuppressants. No genetic engineering details were shared.

Tumor Testing & Safety Checks:

No human safety data has been published yet. However, the NRI previously tested this approach in non-human primates and found long-term survival of the cells without tumor formation.

The Phase 1 trial is designed to follow each participant for at least 12 months to monitor safety and any signs of overgrowth.

Timeline:
FDA Approval: August 2023
First Patient Treated: September 9, 2024
Monitoring Period: 12+ months

Region Skane/STEM-PD Trial:HeSC Cells (UK & Sweden)

(You can read more about it here and here)

Who’s Running It:

The STEM-PD trial is being run by Regione Skane across clinical sites in the UK and Sweden. Surgery is being performed in Lund, Sweden. Imaging is conducted at Invicro in London for UK participants.

Participants:

8 adults with Parkinson’s disease who still had motor symptoms despite being on stable medications.
Each participant underwent one surgery to receive the transplant, and they’ll be followed for 36 months to assess safety and early signs of benefit.

What They’re Testing:

This study is testing whether dopamine progenitor cells (immature cells that can grow into functional dopamine neurons) can be safely transplanted into the brain and potentially improve Parkinson’s symptoms.

The cells were transplanted into the putamen, a key region affected in Parkinson’s that controls movement.

Cell Count:

Participants were split into two dose groups:

Dose 1: 3.54 million cells per side (7.08 million total)
Dose 2: Double that dose, 7.08 million per side (14.16 million total)

Each dose is calculated to target a specific number of surviving dopamine neurons: 100,000 neurons per putamen for Dose 1, and 200,000 for Dose 2.

How the Stem Cells Were Made:

The cells come from human embryonic Stem Cells that were originally created in a lab using leftover embryos from IVF.

Scientists then spent 16 days carefully turning these stem cells into the kind of brain cells that make dopamine. The same type that are lost in Parkinson’s disease.

These dopamine-making cells, called STEM-PD, are frozen and tested thoroughly to make sure they’re safe before being used in people.

Once transplanted into the brain, they gradually grow into working dopamine cells over several months and start doing the job of the lost ones.

Tumor Testing & Safety Checks:

Before trying these cells in people, scientists tested the exact same batch in animals. In those tests, the cells:

Survived long-term and connected properly with the brain
Helped improve movement symptoms caused by Parkinson’s
Did not cause tumors
Stayed in place and didn’t spread to other parts of the body
Showed no signs of toxicity or harmful side effects

Now that the trial is in humans, safety is being closely monitored for three full years after the transplant. This includes regular check-ups, brain scans (like MRI and PET), and blood tests to check for any immune reactions.

What They’re Measuring:

Primary Outcomes:

Safety: Number and nature of serious adverse events (12 months and again from 12–36 months)
No signs of abnormal growths on brain scans (MRI)

Secondary Outcomes:

Motor function (UPDRS, peg tests, sit-stand-walk tests)
Cognitive testing (MoCA, HVLT-R, Stroop, Boston Naming, etc.)
Quality of life scales (PDQ-39, EQ-5D-5L)

Medication dose changes

Exploratory Outcomes:

PET brain scans at 6, 12, 24, and 36 months to check if the new dopamine cells are surviving and working properly
Wearable sensors on the wrist to track movement problems like stiffness, shaking, and symptom ups and downs throughout the day
Tests on spinal fluid and blood to check for inflammation or immune system reactions
Response to Parkinson’s medication (L-dopa) measured over time to see if effects improve or change after the transplant

What They’ve Found so far

Dopamine Cells Survived: PET brain scans taken 6 to 12 months after surgery show that the transplanted cells are alive and surviving in the brain. A key sign the therapy is working as intended.

Integration in the Brain: The dopamine progenitor cells appear to have settled into the target area (the putamen), which is responsible for controlling movement.

On Track for Dose Escalation: The first four participants received the lower dose and tolerated it well. Based on these early safety and imaging results, the trial has moved ahead with the higher dose group.
No Major Safety Issues Reported: So far, there have been no reports of serious complications related to the transplant. Safety monitoring is ongoing and includes brain scans, blood tests, and regular check-ins over 36 months.

Timeline:

Start: 2022

Follow-up duration: 36 months per participant

What’s Next:

The higher-dose group will now move forward with surgery.
Participants will continue to be followed for 36 months, with additional imaging and clinical assessments along the way.

Reviews

Cell-therapy for Parkinson’s disease: a systematic review and meta-analysis 2023 – China

(you can read the full review here)

This research team started by reviewing 106 clinical studies where some form of cell or tissue therapy was used to treat PD. But most studies were too small, too vague, or used mixed types of cells. So, they narrowed it down to the 11 best trials. Ones that used a single, clearly defined cell type and had real data to compare before and after treatment.

These 11 trials Involved 210 Parkinson’s patients

Used homogenous cell types like:

Mesenchymal Stem Cells (MSCs) – often from donor umbilical cords or bone marrow

Neural Progenitor Cells – early-stage brain cells

What did they find?

Cell Therapy Helped Reduce Parkinson’s Symptoms

On average, patients had improvements in movement, daily function, and overall symptoms.

These benefits were measured using a standard scale called the UPDRS (Unified Parkinson’s Disease Rating Scale).
➤ The biggest gains were in motor skills, especially in patients off their medication.

Some Cells Worked Better Than Others

Allogeneic MSCs (from donors) helped more than autologous MSCs (from the patient’s own body).
Why? The donor MSCs seemed to calm the immune system and protect the brain, even if they didn’t turn into new brain cells.
Neural progenitor cells (implanted surgically) also helped, possibly by replacing damaged brain cells, but this isn’t fully proven yet.

IV vs. Brain Surgery: Which Worked Better?

Surprisingly, both worked!

IV infusions (simple injections into the bloodstream) helped patients improve. Likely due to healing signals sent out by the cells.
Surgical implants into the brain showed similar results. But with higher risks (like surgical side effects or abnormal movements).

So, you might not need brain surgery to benefit, at least, not with the right type of cells.

What Were the Limitations?

The review also pointed out some big challenges:

1. Cell Prep Was All Over the Place

Some studies grew their cells in ultra-clean labs (GMP compliant), while others didn’t say how their cells were made.
Some tested cell quality; others didn’t.
Many didn’t explain how they confirmed the cells could help with Parkinson’s.

2. Cell Types and Doses Were Inconsistent

Some used 1 million cells, others used 10 million.
Some gave one treatment; others gave multiple.
Not all cells were designed to become brain cells which might explain why some treatments didn’t work.

3. Short Follow-Ups

Most patients were only followed for 3–24 months.
We still don’t know how long the benefits last. Or if long-term problems might appear later.

4. Small Study Sizes

Most trials had fewer than 30 patients.

We need bigger studies to confirm results and learn who benefits most.

Was It Safe?

Yes the treatments were generally safe:

No tumors or major immune rejection.
Side effects were rare and mild, like fever or vein inflammation.
A few patients had involuntary movements after treatment (called GID), but this was very uncommon.

Their Bottom Line

Cell therapy for Parkinson’s looks promising but it’s not a cure yet.

It can improve symptoms, especially motor skills, and appears to be safe in the short term.
Donor-derived MSCs and neural cells may help in different ways. One by healing signals, the other by cell replacement.

But the field needs more consistency, better-quality trials, and longer follow-up to know how to use it best.

Efficacy and efficacy influencing factors of stem cell transplantation on patients with Parkinson’s disease: a systematic review and meta-analysis: China

(you can read the full review here)

This team in China looked at 9 clinical studies involving 129 people with Parkinson’s disease who were treated with different types of stem cell transplants. These were real medical trials that tested whether injecting stem cells, like those from bone marrow or umbilical cords could actually improve symptoms.

Their goal?
To find out if stem cell therapy works, how well it works, and what factors might affect the results. Like the type of stem cell used or how the cells were delivered.

Types of cells they looked at

Umbilical cord mesenchymal stem cells (UCMSCs)
Bone marrow mesenchymal stem cells (BMMSCs)
Neural stem cells (NSCs)
Human retinal pigment epithelium (RPE) cells
They only looked at studies that used one clear type of stem cell, not a mix of different cells or cells from fetal tissue.

Average Success Rate

The average improvement across all 9 studies was:
WMD = −14.86 (95% CI: −16.62 to −13.10),
which is considered a clinically significant reduction in Parkinson’s symptoms.

In simple terms, On average, people who received stem cell therapy improved noticeably compared to those who didn’t. Their symptoms became milder, and their overall condition got better over a 12-month period.
All studies showed some improvement:
Every trial included in the review showed that patients got better after stem cell treatment, even if they used different types of cells or delivery methods.
The results were very consistent:
The outcomes across all studies were surprisingly similar, which is a good sign that the treatment really works. Even without guiding the cells to the exact spot

Delivery methods and which was most effective

Intravascular injection (through a vein)
Intrathecal injection (into the spine)
Intraventricular injection (into the brain)
Intravascular was the most effective, showing the largest and most consistent improvement in symptoms.

Injecting cells through the bloodstream may help them circulate more widely and survive better than direct brain injections.

How they discussed MSCs helping in Parkinson’s

MSCs likely don’t work by turning into new brain cells.
Instead, they seem to release healing signals that reduce inflammation, calm the immune system, and protect existing neurons.
This supports the idea that MSCs act like “cellular support crews,” improving the brain environment rather than replacing lost dopamine cells directly.

Limitations they acknowledged

Most studies were small and not randomized, which can introduce bias.
Follow-up times were usually short. Only one study looked beyond 12 months, so we don’t know if benefits last long-term.
Differences in how cells were prepared and given (like dose or quality) weren’t analyzed.
No sham surgery controls were used, so the placebo effect can’t be ruled out.
Not enough data to compare the different types of MSCs in a head-to-head way.

Their overall conclusion:

“Data from controlled trials suggest that stem cell transplantation as a therapy for Parkinson’s disease can be effective for at least 12 months. The factors that may influence its curative effect are time after transplantation and stem cell types”

In Lehman’s terms:

Stem cell therapy does help people with Parkinson’s, at least in the first year after treatment.
The results depend on what kind of stem cells are used and how long it’s been since the transplant.

More long-term studies are needed, but early results are promising.

Previous Trials (post 2020)

Hope Biosciences HB-adMSC Trial (USA)

(You can read the full study here)

Who’s Running It:

The trial was conducted at Hope Biosciences Stem Cell Research Foundation in the United States. It tested whether multiple intravenous infusions of a patient’s own stem cells (HB-adMSCs) could help slow disease progression in people with Parkinson’s disease.

Participants:

18 adults diagnosed with mild to moderate Parkinson’s disease.
All participants were on stable Parkinson’s medication regimens during the study

What They’re Testing:

This study tested whether autologous mesenchymal stem cells (HB-adMSCs), derived from each participant’s own fat tissue, could be used to reduce inflammation and improve clinical outcomes in Parkinson’s disease when administered through a series of IV infusions.

The idea is that these cells may help regulate immune responses, reduce neuroinflammation, and potentially protect brain cells involved in movement.

How the Stem Cells Were Made:

Each participant underwent a small fat biopsy, from which adipose-derived mesenchymal stem cells (adMSCs) were isolated and expanded in a lab.

These HB-adMSCs were:

Autologous (from the same patient)

Cell Count & Dosing:

Each participant in the treatment group received:

6 intravenous (IV) infusions
One infusion every 4 weeks over a 32-week period

The placebo group received 6 matched saline infusions on the same schedule.

Throughout the study and 52-week follow-up:

Patients were closely monitored for tumor formation, cell overgrowth, or unusual responses
(Ongoing safety surveillance to catch delayed adverse effects).
No cases of tumor growth, cancer, or abnormal cell proliferation were reported.
(Supports a strong safety profile over the treatment duration).
No serious adverse events were linked to the stem cell infusions.
(Indicates the treatment was well tolerated in all participants).

What They’re Measuring:

Primary Outcome:

Safety and tolerability: frequency and type of adverse events

Secondary Outcomes:

Changes in motor symptoms using the Unified Parkinson’s Disease Rating Scale (UPDRS)
Neuroinflammatory markers in blood (e.g., monocyte subtypes)
Changes in neurodegeneration biomarkers (e.g., Neurofilament light chain, NfL)

General clinical progression

Results So Far:

No treatment-related serious adverse events occurred
One participant had a transient seizure (not related to treatment)
Treated patients showed improvement in UPDRS motor scores, while placebo patients worsened
Blood analysis showed a reduction in pro-inflammatory monocytes in treated patients
NfL levels trended lower in the treatment group (a positive neuroprotective signal, though not statistically significant)

Timeline:

Start Date: 2021
Treatment Period: 32 weeks
Follow-up Completed: 52 weeks

University of Texas Autologous MSC Trial (United States)

(You can read about the study & results here and here.)

Who’s Running It:

This trial is being led by Dr. Mya Schiess at The University of Texas Health Science Center in Houston, with support from the Michael J. Fox Foundation.

Participants:

44 adults with Parkinson’s disease took part.

Average age: 67 years
All were diagnosed 3–10 years prior
They had clear motor symptoms but were still responsive to medication

No one had cognitive issues, psychosis, or major heart/lung disease

What They’re Testing:

The study tested whether mesenchymal stem cells (MSCs) from donor bone marrow could improve motor symptoms when given in repeat infusions.

Three groups were compared:

Placebo group (no real stem cells)
2-dose group (2 real infusions, 1 placebo)
3-dose group (3 real infusions)

Each infusion was spaced 4 months apart, and each dose was based on body weight:

10 million cells per kilogram

That’s one of the highest doses ever tested for Parkinson’s.

How the Cells Were Made:

The study did not specify how the MSCs were sourced or processed.
We know only that they came from donor bone marrow and were allogeneic (not from the patient themselves).
Details on how the cells were expanded, tested, or purified were not included in the public record.

What They’re Measuring:

Primary Outcome:

Motor function, using the MDS-UPDRS Part III scale (a gold standard tool in PD research). It’s basically researchers measuring how well patients could move using a trusted Parkinson’s rating scale. The lower the score, the better the moot function.

Secondary Outcomes:

Safety and side effects
Immune response to the donor cells
Mobility (Timed-Up-and-Go test)
Daily function and quality of life (PDQ-39, EQ-5D, Schwab & England scales)
Cognition, mood, anxiety, and smell
Biomarkers in blood and spinal fluid, including:
- NfL (a marker of nerve damage)
- Cytokines, chemokines, growth factors, and neurotransmitters
- Alpha-synuclein levels

Results So Far:

Motor Symptoms (MDS-UPDRS-III scores):

Placebo Group: Improved by 3 points
2 MSC Infusions: Improved by 11 points
3 MSC Infusions: Improved by 16 points

The more MSC infusions, the better the improvement
(and the differences were statistically significant – p < 0.001)

NfL Biomarker:All groups showed increases in serum NfL, including placebo. Serum NfL is a blood marker that shows how much stress or damage your nerves are under.

But in the 3-dose group, NfL levels were positively correlated with motor improvement
This suggests NfL could be a useful biomarker for tracking recovery

Why It Matters:

This trial shows that high-dose, repeated stem cell infusions may have a real impact on slowing or even reversing motor decline in Parkinson’s.

And importantly

The patients who got all 3 MSC infusions did the best.

It also hints that NfL, a blood-based biomarker, might help doctors track who’s responding to treatment in the future.

Conclusion

Here’s what we can learn from all the recent stem cell trials for Parkinson’s disease:

Most Patients Got Better
Nearly every trial reported improvements. Symptoms like movement and stiffness improved by 20% to 70%, depending on the study.
Higher Doses Helped More
When studies tested low vs. high doses, the higher doses almost always worked better. Patients moved better and had stronger dopamine activity.
Most Studies Targeted the Brain
The most common method was injecting cells into the brain (the putamen). A few studies used IV infusions, mostly for MSCs.
Asia Leads the Research
Most trials happened in China, Japan, and South Korea. The U.S. also had several.
One Cell Type Stands Out Most trials used iPSC dopamine cells.
These are lab-made brain cells grown from skin or blood. A few studies used embryonic or mesenchymal cells, but less often.
MSCs likely don’t work by turning into new brain cells.
Instead, they seem to release healing signals that reduce inflammation, calm the immune system, and protect existing neurons
No Serious Safety Issues Reported
None of the trials reported tumors or serious side effects linked to the stem cells. Most patients tolerated treatment well, even with brain surgery or IV infusions.

What the Trials Can’t Tell Us Yet

Small Groups of Patients
Most studies only involved a handful of people. That’s not enough to prove the treatment works for everyone.
Short Follow-Up Time
Many patients were only tracked for 6 to 12 months. We still don’t know how long the benefits last or if risks appear later.
Still in Early Stages
Most of this research is Phase 1 or 2. We don’t yet have large-scale, definitive trials that confirm stem cell therapy truly works for Parkinson’s in the real world.
No Standard for Making the Cells
Each study made and tested its stem cells differently. Some followed strict lab protocols, while others didn’t fully explain their process. This makes it harder to compare results or repeat the findings.
Stem cell therapy may help improve symptoms and slow down progression, especially motor-related ones.
But no trial has shown it can reverse Parkinson’s or restore full brain function yet.

And remember, just because there may be early positive signs in trials, clinics won’t always be using the same processes! This article is purely meant to give you an overview on the current research out there. Please be careful when thinking about treatment!