Creating an on-off switch to test stem cell therapy for Parkinson’s Disease

Sometimes you read about a new study where the researchers did something that just leaves you gob smacked. That’s how I felt when I read a study in the journal Cell Stem Cell about a possible new approach to helping people with Parkinson’s Disease (PD).

More on the gob smacking later. But first the reason for the study.

We know that one of the causes of Parkinson’s disease is the death of dopamine-producing neurons, brain cells that help plan and control body movement. Over the years, researchers have tried different ways to try and replace those cells but getting the cells where they need to be and getting them to integrate into the brain has proved challenging.

A team at the University of Wisconsin-Madison think they may have found a way to fix that. In an article in Drug Target Review  lead researcher Dr. Su-Chun Zhang, explained their approach:

“Our brain is wired in such an accurate way by very specialized nerve cells in particular locations so we can engage in all our complex behaviors. This all depends on circuits that are wired by specific cell types. Neurological injuries usually affect specific brain regions or specific cell types, disrupting circuits. In order to treat those diseases, we have to restore these circuits.”

The researchers took human embryonic stem cells and transformed them into dopamine-producing neurons, then they transplanted those cells into mice specially bred to display PD symptoms. After several months the team were able to show that not only had the mice improved motor skills but that the transplanted neurons were able to connect to the motor-control regions of the brain and also establish connections with regulatory regions of the brain, which prevented over stimulation. In other words, the transplanted cells looked and behaved the way they would in a healthy human brain.

Now here comes the gob smack part. The team wanted to make sure the cells they transplanted were the reason for the improved motor control in the mice. So, they had inserted a genetic on-and-off switch into the stem cells. By using specially designed drugs the researchers were able to switch the cells on or off.

When the cells were switched off the mice’s motor improvements stopped. When they were switched back on, they were restored.

Brilliant right! Well, I thought it was.

Next step is to test this approach in larger animals and, if all continues to look promising, to move into human clinical trials.

CIRM is already funding one clinical trial in Parkinson’s disease. You can read about it here.

CIRM Funded Trial for Parkinson’s Treats First Patient

Dr. Krystof Bankiewicz

Brain Neurotherapy Bio, Inc. (BNB) is pleased to announce the treatment of the first patient in its Parkinson’s gene therapy study.  The CIRM-funded study, led by Dr. Krystof Bankiewicz, is one of the 64 clinical trials funded by the California state agency to date.

Parkinson’s is a neurodegenerative movement disorder that affects one million people in the U.S alone and leads to shaking, stiffness, and problems with walking, balance, and coordination.  It is caused by the breakdown and death of dopaminergic neurons, special nerve cells in the brain responsible for the production of dopamine, a chemical messenger that is crucial for normal brain activity.

The patient was treated at The Ohio State University Wexner Medical Center with a gene therapy designed to promote the production of a protein called GDNF, which is best known for its ability to protect dopaminergic neurons, the kind of cell damaged by Parkinson’s. The treatment seeks to increase dopamine production in the brain, alleviating Parkinson’s symptoms and potentially slowing down the disease progress.

“We are pleased to support this multi-institution California collaboration with Ohio State to take a novel first-in-human gene therapy into a clinical trial for Parkinson’s Disease.” says Maria T. Millan, M.D., President and CEO of CIRM.  “This is the culmination of years of scientific research by the Bankiewicz team to improve upon previous attempts to translate the potential therapeutic effect of GDNF to the neurons damaged in the disease. We join the Parkinson’s community in following the outcome of this vital research opportunity.”

CIRM Board Member and patient advocate David Higgins, Ph.D. is also excited about this latest development.  For Dr. Higgins, advocating for Parkinson’s is a very personal journey since he, his grandmother, and his uncle were diagnosed with the disease.

“Our best chance for developing better treatments for Parkinson’s is to test as many logical approaches as possible. CIRM encourages out-of-the-box thinking by providing funding for novel approaches. The Parkinson’s community is a-buzz with excitement about the GDNF approach and looks to CIRM to identify, fund, and promote these kinds of programs.”

In a news release Dr. Sandra Kostyk, director of the Movement Disorders Division at Ohio State Wexner Medical Center said this approach involves infusing a gene therapy solution deep into a part of the brain affected by Parkinson’s: “This is a onetime treatment strategy that could have ongoing lifelong benefits. Though it’s hoped that this treatment will slow disease progression, we don’t expect this strategy to completely stop or cure all aspects of the disease. We’re cautiously optimistic as this research effort moves forward.” 

Other trial sites located in California that are currently recruiting patients are the University of California, Irvine (UCI) and the University of California, San Francisco (UCSF). Specifically, the Irvine trial site is using the UCI Alpha Stem Cell Clinic, one of five leading medical centers throughout California that make up the CIRM Alpha Stem Cell Clinic (ASSC) Network.  The ASSC Network specializes in the delivery of stem cell therapies by providing world-class, state of the art infrastructure to support clinical research.

For more information on the trial and enrollment eligibility, you can directly contact the study coordinators by email at the trial sites listed:

  1. The Ohio State University: OSUgenetherapyresearch@osumc.edu
  2. University of California, San Francisco: GDNF@ucsf.edu
  3. University of California, Irvine: chewbc@hs.uci.edu

Parkinson’s Disease and Stem Cells

Lila Collins, PhD

A few weeks ago we held a Facebook Live “Ask the Stem Cell Team About Parkinson’s Disease” event. As you can imagine we got lots of questions but, because of time constraints, only had time to answer a few. Thanks to my fabulous CIRM colleagues, Dr. Lila Collins and Dr. Kent Fitzgerald, for putting together answers to some of the other questions. Here they are.

Kent Fitzgerald, PhD

Q: It seems like we have been hearing for years that stem cells can help people with Parkinson’s, why is it taking so long?

A: Early experiments in Sweden using fetal tissue did provide a proof of concept for the strategy of replacing dopamine producing cells damaged or lost in Parkinson’s disease (PD) . At first, this seemed like we were on the cusp of a cell therapy cure for PD, however, we soon learned based on some side effects seen with this approach (in particular dyskinesias or uncontrollable muscle movements) that the solution was not as simple as once thought. 

While this didn’t produce the answer it did provide some valuable lessons.

The importance of dopaminergic (DA) producing cell type and the location in the brain of the transplant.  Simply placing the replacement cells in the brain is not enough. It was initially thought that the best site to place these DA cells is a region in the brain called the SN, because this area helps to regulate movement. However, this area also plays a role in learning, emotion and the brains reward system. This is effectively a complex wiring system that exists in a balance, “rewiring” it wrong can have unintended and significant side effects. 

Another factor impacting progress has been understanding the importance of disease stage. If the disease is too advanced when cells are given then the transplant may no longer be able to provide benefit.  This is because DA transplants replace the lost neurons we use to control movement, but other connected brain systems have atrophied in response to losing input from the lost neurons. There is a massive amount of work (involving large groups and including foundations like the Michael J Fox Foundation) seeking to identify PD early in the disease course where therapies have the best chance of showing an effect.   Clinical trials will ultimately help to determine the best timing for treatment intervention.

Ideally, in addition to the cell therapies that would replace lost or damaged cells we also want to find a therapy that slows or stops the underlying biology causing progression of the disease.

So, I think we’re going to see more gene therapy trials including those targeting the small minority of PD that is driven by known mutations.  In fact, Prevail Therapeutics will soon start a trial in patients with GBA1 mutations. Hopefully, replacing the enzyme in this type of genetic PD will prevent degeneration.

And, we are also seeing gene therapy approaches to address forms of PD that we don’t know the cause, including a trial to rescue sick neurons with GDNF which is a neurotrophic factor (which helps support the growth and survival of these brain cells) led by Dr Bankiewicz  and trials by Axovant and Voyager, partnered with Neurocrine aimed at restoring dopamine generation in the brain.

 A small news report came out earlier this year about a recently completed clinical trial by Roche Pharma and Prothena. This addressed the build up in the brain of what are called lewy bodies, a problem common to many forms of PD. While the official trial results aren’t published yet, a recent press release suggests reason for optimism.  Apparently, the treatment failed to statistically improve the main clinical measurement, but other measured endpoints saw improvement and it’s possible an updated form of this treatment will be tested again in the hopes of seeing an improved effect.

Finally, I’d like to call attention to the G force trials. Gforce is a global collaborative effort to drive the field forward combining lessons learned from previous studies with best practices for cell replacement in PD.  These first-in-human safety trials to replace the dopaminergic neurons (DANs) damaged by PD have shared design features including identifying what the best goals are and how to measure those.

The CIRA trial, Dr Jun Takahashi

The NYSTEM PD trial, Dr Lorenz Studer

The EUROSTEMPD trial, Dr Roger Barker.

And the Summit PD trial, Dr Jeanne Loring of Aspen Neuroscience.

Taken together these should tell us quite a lot about the best way to replace these critical neurons in PD.

As with any completely novel approach in medicine, much validation and safety work must be completed before becoming available to patients

The current approach (for cell replacement) has evolved significantly from those early studies to use cells engineered in the lab to be much more specialized and representing the types believed to have the best therapeutic effects with low probability of the side effects (dyskinesias) seen in earlier trials. 

If we don’t really know the cause of Parkinson’s disease, how can we cure it or develop treatments to slow it down?

PD can now be divided into major categories including 1. Sporadic, 2. Familial. 

For the sporadic cases, there are some hallmarks in the biology of the neurons affected in the disease that are common among patients.  These can be things like oxidative stress (which damages cells), or clumps of proteins (like a-synuclein) that serve to block normal cell function and become toxic, killing the DA neurons. 

The second class of “familial” cases all share one or more genetic changes that are believed to cause the disease.  Mutations in genes (like GBA, LRRK2, PRKN, SNCA) make up around fifteen percent of the population affected, but the similarity in these gene mutations make them attractive targets for drug development.

CIRM has funded projects to generate “disease in a dish” models using neurons made from adults with Parkinson’s disease.   Stem cell-derived models like this have enabled not only a deep probing of the underlying biology in Parkinson’s, which has helped to identify new targets for investigation, but have also allowed for the testing of possible therapies in these cell-based systems. 

iPSC-derived neurons are believed to be an excellent model for this type of work as they can possess known familial mutations but also show the rest of the patients genetic background which may also be a contributing factor to the development of PD. They therefore contain both known and unknown factors that can be tested for effective therapy development.

I have heard of scientists creating things called brain organoids, clumps of brain cells that can act a little bit like a brain. Can we use these to figure out what’s happening in the brain of people with Parkinson’s and to develop treatments?

There is considerable excitement about the use of brain organoids as a way of creating a model for the complex cell-to-cell interactions in the brain.  Using these 3D organoid models may allow us to gain a better understanding of what happens inside the brain, and develop ways to treat issues like PD.

The organoids can contain multiple cell types including microglia which have been a hot topic of research in PD as they are responsible for cleaning up and maintaining the health of cells in the brain.  CIRM has funded the Salk Institute’s Dr. Fred Gage’s to do work in this area.

If you go online you can find lots of stem cells clinics, all over the US, that claim they can use stem cells to help people with Parkinson’s. Should I go to them?

In a word, no! These clinics offer a wide variety of therapies using different kinds of cells or tissues (including the patient’s own blood or fat cells) but they have one thing in common; none of these therapies have been tested in a clinical trial to show they are even safe, let alone effective. These clinics also charge thousands, sometimes tens of thousands of dollars these therapies, and because it’s not covered by insurance this all comes out of the patient’s pocket.

These predatory clinics are peddling hope, but are unable to back it up with any proof it will work. They frequently have slick, well-designed websites, and “testimonials” from satisfied customers. But if they really had a treatment for Parkinson’s they wouldn’t be running clinics out of shopping malls they’d be operating huge medical centers because the worldwide need for an effective therapy is so great.

Here’s a link to the page on our website that can help you decide if a clinical trial or “therapy” is right for you.

Is it better to use your own cells turned into brain cells, or cells from a healthy donor?

This is the BIG question that nobody has evidence to provide an answer to. At least not yet.

Let’s start with the basics. Why would you want to use your own cells? The main answer is the immune system.  Transplanted cells can really be viewed as similar to an organ (kidney, liver etc) transplant. As you likely know, when a patient receives an organ transplant the patient’s immune system will often recognize the tissue/organ as foreign and attack it. This can result in the body rejecting what is supposed to be a life-saving organ. This is why people receiving organ transplants are typically placed on immunosuppressive “anti-rejection “drugs to help stop this reaction. 

In the case of transplanted dopamine producing neurons from a donor other than the patient, it’s likely that the immune system would eliminate these cells after a short while and this would stop any therapeutic benefit from the cells.  A caveat to this is that the brain is a “somewhat” immune privileged organ which means that normal immune surveillance and rejection doesn’t always work the same way with the brain.  In fact analysis of the brains collected from the first Swedish patients to receive fetal transplants showed (among other things) that several patients still had viable transplanted cells (persistence) in their brains.

Transplanting DA neurons made from the patient themselves (the iPSC method) would effectively remove this risk of the immune system attack as the cells would not be recognized as foreign.

CIRM previously funded a discovery project with Jeanne Loring from Scripps Research Institute that sought to generate DA neurons from Parkinson’s patients for use as a potential transplant therapy in these same patients.   This project has since been taken on by a company formed, by Dr Loring, called Aspen Neuroscience.  They hope to bring this potential therapy into clinical trials in the near future.    

A commonly cited potential downside to this approach is that patients with genetic (familial) Parkinson’s would be receiving neurons generated with cells that may have the same mutations that caused the problem in the first place. However, as it can typically take decades to develop PD, these cells could likely function for a long time. and prove to be better than any current therapies.

Creating cells from each individual patient (called autologous) is likely to be very expensive and possibly even cost-prohibitive. That is why many researchers are working on developing an “off the shelf” therapy, one that uses cells from a donor (called allogeneic)would be available as and when it’s needed.

When the coronavirus happened, it seemed as if overnight the FDA was approving clinical trials for treatments for the virus. Why can’t it work that fast for Parkinson’s disease?

While we don’t know what will ultimately work for COVID-19, we know what the enemy looks like.  We also have lots of experience treating viral infections and creating vaccines.  The coronavirus has already been sequenced, so we are building upon our understanding of other viruses to select a course to interrupt it.  In contrast, the field is still trying to understand the drivers of PD that would respond to therapeutic targeting and therefore, it’s not precisely clear how best to modify the course of neurodegenerative disease.  So, in one sense, while it’s not as fast as we’d like it to be, the work on COVID-19 has a bit of a head start.

Much of the early work on COVID-19 therapies is also centered on re-purposing therapies that were previously in development.  As a result, these potential treatments have a much easier time entering clinical trials as there is a lot known about them (such as how safe they are etc.).  That said, there are many additional therapeutic strategies (some of which CIRM is funding) which are still far off from being tested in the clinic. 

The concern of the Food and Drug Administration (FDA) is often centered on the safety of a proposed therapy.  The less known, the more cautious they tend to be. 

As you can imagine, transplanting cells into the brain of a PD patient creates a significant potential for problems and so the FDA needs to be cautious when approving clinical trials to ensure patient safety.

Stem Cells for Parkinson’s Disease

While the world has been turned upside down by the coronavirus pandemic, the virus poses an increased threat to people with Parkinson’s disease (PD). Having a compromised immune system, particularly involving the lungs, means people with PD are at higher risk of some of the more dangerous complications of COVID-19. So, this seems like an appropriate time for CIRM to hold a special Facebook Live “Ask the Stem Cell Team” About Parkinson’s disease.

We are holding the event on Tuesday, May 5th at noon PDT.

The initial reason for the Facebook Live was the CIRM Board approving almost $8 million for Dr. Krystof Bankiewicz at Brain Neurotherapy Bio, Inc. to run a Phase 1 clinical trial targeting PD. Dr. Bankiewicz is using a gene therapy approach to promote the production of a protein called GDNF, which is best known for its ability to protect dopaminergic neurons, the kind of cell damaged by Parkinson’s. The approach seeks to increase dopamine production in the brain, alleviating PD symptoms and potentially slowing down the disease progress.

Dr. Bankiewicz will be joined by two of CIRM’s fine Science Officers, Dr. Lila Collins and Dr. Kent Fitzgerald. They’ll talk about the research targeting Parkinson’s that CIRM is funding plus other promising research taking place.

And we are delighted to have a late addition to the team. Our CIRM Board member and patient advocate for Parkinson’s disease, Dr. David Higgins. David has a long history of advocacy for PD and adds the invaluable perspective of someone living with PD.

As always, we want this to be as interactive as possible, so we want to get your questions. You can do this on the day, posting them alongside the live feed, or you can send them to us ahead of time at info@cirm.ca.gov. We’ll do our best to answer as many as we can on the day, and those we don’t get to during the broadcast we’ll answer in a later blog.

We look forward to seeing you there.

Stem Cell Agency Approves Funding for Clinical Trials Targeting Parkinson’s Disease and Blindness

The governing Board of the California Institute for Regenerative Medicine (CIRM) yesterday invested $32.92 million to fund the Stem Cell Agency’s first clinical trial in Parkinson’s disease (PD), and to support three clinical trials targeting different forms of vision loss.

This brings the total number of clinical trials funded by CIRM to 60.

The PD trial will be carried out by Dr. Krystof Bankiewicz at Brain Neurotherapy Bio, Inc. He is using a gene therapy approach to promote the production of a protein called GDNF, which is best known for its ability to protect dopaminergic neurons, the kind of cell damaged by Parkinson’s. The approach seeks to increase dopamine production in the brain, alleviating PD symptoms and potentially slowing down the disease progress.

David Higgins, PhD, a CIRM Board member and patient advocate for Parkinson’s says there is a real need for new approaches to treating the disease. In the US alone, approximately 60,000 people are diagnosed with PD each year and it is expected that almost one million people will be living with the disease by 2020.

“Parkinson’s Disease is a serious unmet medical need and, for reasons we don’t fully understand, its prevalence is increasing. There’s always more outstanding research to fund than there is money to fund it. The GDNF approach represents one ‘class’ of potential therapies for Parkinson’s Disease and has the potential to address issues that are even broader than this specific therapy alone.”

The Board also approved funding for two clinical trials targeting retinitis pigmentosa (RP), a blinding eye disease that affects approximately 150,000 individuals in the US and 1.5 million people around the world. It is caused by the destruction of light-sensing cells in the back of the eye known as photoreceptors.  This leads to gradual vision loss and eventually blindness.  There are currently no effective treatments for RP.

Dr. Henry Klassen and his team at jCyte are injecting human retinal progenitor cells (hRPCs), into the vitreous cavity, a gel-filled space located in between the front and back part of the eye. The proposed mechanism of action is that hRPCs secrete neurotrophic factors that preserve, protect and even reactivate the photoreceptors, reversing the course of the disease.

CIRM has supported early development of Dr. Klassen’s approach as well as preclinical studies and two previous clinical trials.  The US Food and Drug Administration (FDA) has granted jCyte Regenerative Medicine Advanced Therapy (RMAT) designation based on the early clinical data for this severe unmet medical need, thus making the program eligible for expedited review and approval.

The other project targeting RP is led by Dr. Clive Svendsen from the Cedars-Sinai Regenerative Medicine Institute. In this approach, human neural progenitor cells (hNPCs) are transplanted to the back of the eye of RP patients. The goal is that the transplanted hNPCs will integrate and create a protective layer of cells that prevent destruction of the adjacent photoreceptors. 

The third trial focused on vision destroying diseases is led by Dr. Sophie Deng at the University of California Los Angeles (UCLA). Dr. Deng’s clinical trial addresses blinding corneal disease by targeting limbal stem cell deficiency (LSCD). Under healthy conditions, limbal stem cells (LSCs) continuously regenerate the cornea, the clear front surface of the eye that refracts light entering the eye and is responsible for the majority of the optical power. Without adequate limbal cells , inflammation, scarring, eye pain, loss of corneal clarity and gradual vision loss can occur. Dr. Deng’s team will expand the patient’s own remaining LSCs for transplantation and will use  novel diagnostic methods to assess the severity of LSCD and patient responses to treatment. This clinical trial builds upon previous CIRM-funded work, which includes early translational and late stage preclinical projects.

“CIRM funds and accelerates promising early stage research, through development and to clinical trials,” says Maria T. Millan, MD, President and CEO of CIRM. “Programs, such as those funded today, that were novel stem cell or gene therapy approaches addressing a small number of patients, often have difficulty attracting early investment and funding. CIRM’s role is to de-risk these novel regenerative medicine approaches that are based on rigorous science and have the potential to address unmet medical needs. By de-risking programs, CIRM has enabled our portfolio programs to gain significant downstream industry funding and partnership.”

CIRM Board also awarded $5.53 million to Dr. Rosa Bacchetta at Stanford to complete work necessary to conduct a clinical trial for IPEX syndrome, a rare disease caused by mutations in the FOXP3 gene. Immune cells called regulatory T Cells normally function to protect tissues from damage but in patients with IPEX syndrome, lack of functional Tregs render the body’s own tissues and organs to autoimmune attack that could be fatal in early childhood.  Current treatment options include a bone marrow transplant which is limited by available donors and graft versus host disease and immune suppressive drugs that are only partially effective. Dr. Rosa Bacchetta and her team at Stanford will use gene therapy to insert a normal version of the FOXP3 gene into the patient’s own T Cells to restore the normal function of regulatory T Cells.

The CIRM Board also approved investing $15.80 million in four awards in the Translational Research program. The goal of this program is to help promising projects complete the testing needed to begin talking to the US Food and Drug Administration (FDA) about holding a clinical trial.

The TRAN1 Awards are summarized in the table below:

ApplicationTitleInstitutionAward Amount
TRAN1 11536Ex Vivo Gene Editing of Human Hematopoietic Stem Cells for the Treatment of X-Linked Hyper IgM Syndrome  UCLA $4,896,628
TRAN1 11555BCMA/CS1 Bispecific CAR-T Cell Therapy to Prevent Antigen Escape in Multiple Myeloma  UCLA $3,176,805
TRAN1 11544 Neural Stem cell-mediated oncolytic immunotherapy for ovarian cancer  City of Hope $2,873,262
TRAN1 11611Development of a human stem cell-derived inhibitory neuron therapeutic for the treatment of chronic focal epilepsyNeurona Therapeutics$4,848,750