A little history in the making by helping the tiniest patients

Dr. Diana Farmer stands with Dr. Aijun Wang and their UC Davis research team.

It’s appropriate that at the start of Women’s History Month, UC Davis’ Dr. Diana Farmer is making a little history of her own. She launched the world’s first clinical trial using stem cells to treat spina bifida before the child is born.

Spina bifida is a birth defect caused when a baby’s spinal cord fails to develop properly in the womb. In myelomeningocele, the most severe form of spina bifida, a portion of the spinal cord or nerves is exposed in a sac through an opening in the spine. Most people with myelomeningocele have changes in their brain structure, leg weakness, and bladder and bowel dysfunction. 

Illustration of spina bifida

While surgery can help, Dr. Farmer says it is far from perfect: “Currently, the standard of care for our patients is fetal surgery, which, while promising, still leaves more than half of children with spina bifida unable to walk independently. There is an extraordinary need for a treatment that prevents or lessens the severity of this devastating condition. Our team has spent more than a decade working up to this point of being able to test such a promising therapy.” 

The team at UC Davis – in a CIRM-funded study – will use a stem cell “patch” that is placed over the exposed spinal cord, then surgically close the opening, hopefully allowing the stem cells to regenerate and protect the spinal cord.

In a news release Dr. Aijun Wang, a stem cell bioengineer, says the team has been preparing for this trial for years, helping show in animals that it is safe and effective. He is hopeful it will prove equally safe and effective in people: “Our cellular therapy approach, in combination with surgery, should encourage tissue regeneration and help patients avoid devastating impairments throughout their lives.” 

Dr. Farmer says the condition, while rare, disproportionately affects Latinx babies and if the procedure works could have an enormous impact on their lives and the lives of their families: “A successful treatment for MMC would relieve the tremendous emotional and economic cost burden on families. We know it initially costs approximately $532,000 per child with spina bifida. But the costs are likely several million dollars more due to ongoing treatments, not to mention all the pain and suffering, specialized childcare, and lost time for unpaid caregivers such as parents.”

Here is video of two English bulldogs who had their spinal injuries repaired at UC Davis using stem cells. This was part of the research that led to the clinical trial led by Dr. Farmer and Dr. Wang.

Stem cell gene therapy for Fabry disease shows positive results in patients

Darren Bidulka rests after his modified blood stem cells were transplanted into him at the Foothills Medical Centre in Calgary in 2017, allowing him to stop his enzyme therapy. (From left): Dr. Jeffrey Medin, Medical College of Wisconsin, Dr. Aneal Khan, the experimental trial lead in Calgary, and Darren Bidulka. Image Credit: Darren Bidulka

Fabry disease is an X-linked genetic disorder that can damage major organs and shorten lifespan. Without a functional version of a gene called GLA, our bodies are unable to make the correct version of an enzyme that breaks down a fat, and that in turn can lead to problems in the kidneys, heart and brain. It is estimated that one person in 40,000 to 60,000 has the disease and it affects men more severely than women since men only have one copy of the X chromosome. Current treatment consists of enzyme therapy infusions every two weeks but there is currently no cure for Fabry disease. 

However, a Canadian research team is conducting the world’s first pilot study to treat Fabry disease using a stem cell gene therapy approach. The researchers collected the patient’s own blood stem cells and used gene therapy to insert copies of the fully functional gene into the stem cells, allowing them to make the correct version of the enzyme. The newly modified stem cells were then transplanted back into each patient.

Five men participated in this trial and the results so far have been very encouraging. After treatment with the stem cell gene therapy, all patients began producing the corrected version of the enzyme to near normal levels within one week. With these initial results, all five patients were allowed to stop their biweekly enzyme therapy infusions. So far, only three patients decided to do so and are stable.

In a news release, Darren Bidulka, the first patient to be treated in the study, talked about how life changing this stem cell gene therapy has been for him.

“I’m really happy that this worked. What an amazing result in an utterly fascinating experience. I consider this a great success. I can lead a more normal life now without scheduling enzyme therapy every two weeks. This research is also incredibly important for many patients all over the world, who will benefit from these findings.”

CIRM is no stranger to stem cell gene therapy and its potential having funded clinical trials in various areas such as severe combined immunodeficiency (bubble baby disease), cystinosis, sickle cell disease, and various others. The broad range of genetic diseases it has been used in to treat patients further highlights its importance in scientific research.

The full results of this study were published in Nature Communications.

A word from our Chair, several in fact

In 2005, the New Oxford American Dictionary named “podcast” its word of the year. At the time a podcast was something many had heard of but not that many actually tuned in to. My how times have changed. Now there are some two million podcasts to chose from, at least according to the New York Times, and who am I to question them.

Yesterday, in the same New York Times, TV writer Margaret Lyons, wrote about how the pandemic helped turn her from TV to podcasts: “Much in the way I grew to prefer an old-fashioned phone call to a video chat, podcasts, not television, became my go-to medium in quarantine. With their shorter lead times and intimate production values, they felt more immediate and more relevant than ever before.”

I mention this because an old colleague of ours at CIRM, Neil Littman, has just launched his own podcast and the first guest on it was Jonathan Thomas, Chair of the CIRM Board. Their conversation ranged from CIRM’s past to the future of the regenerative field as a whole, with a few interesting diversions along the way. It’s fun listening. And as Margaret Lyons said it might be more immediate and more relevant than ever before.

Charting a course for the future

A new home for stem cell research?

Have you ever been at a party where someone says “hey, I’ve got a good idea” and then before you know it everyone in the room is adding to it with ideas and suggestions of their own and suddenly you find yourself with 27 pages of notes, all of them really great ideas. No, me neither. At least, not until yesterday when we held the first meeting of our Scientific Strategy Advisory Panel.

This is a group that was set up as part of Proposition 14, the ballot initiative that refunded CIRM last November (thanks again everyone who voted for that). The idea was to create a panel of world class scientists and regulatory experts to help guide and advise our Board on how to advance our mission. It’s a pretty impressive group too. You can see who is on the SSAP here.  

The meeting involved some CIRM grantees talking a little about their work but mostly highlighting problems or obstacles they considered key issues for the future of the field as a whole. And that’s where the ideas and suggestions really started flowing hard and fast.

It started out innocently enough with Dr. Amander Clark of UCLA talking about some of the needs for Discovery or basic research. She advocated for a consortium approach (this quickly became a theme for many other experts) with researchers collaborating and sharing data and findings to help move the field along.

She also called for greater diversity in research, including collecting diverse cell samples at the basic research level, so that if a program advanced to later stages the findings would be relevant to a wide cross section of society rather than just a narrow group.

Dr. Clark also said that as well as supporting research into neurodegenerative diseases, such as Alzheimer’s and Parkinson’s, there needed to be a greater emphasis on neurological conditions such as autism, bipolar disorder and other mental health problems.

(CIRM is already committed to both increasing diversity at all levels of research and expanding mental health research so this was welcome confirmation we are on the right track).

Dr. Mike McCun called for CIRM to take a leadership role in funding fetal tissue research, things the federal government can’t or won’t support, saying this could really help in developing an understanding of prenatal diseases.

Dr. Christine Mummery, President of ISSCR, advocated for support for early embryo research to deepen our understanding of early human development and also help with issues of infertility.

Then the ideas started coming really fast:

  • There’s a need for knowledge networks to share information in real-time not months later after results are published.
  • We need standardization across the field to make it easier to compare study results.
  • We need automation to reduce inconsistency in things like feeding and growing cells, manufacturing cells etc.
  • Equitable access to CRISPR gene-editing treatments, particularly for underserved communities and for rare diseases where big pharmaceutical companies are less likely to invest the money needed to develop a treatment.
  • Do a better job of developing combination therapies – involving stem cells and more traditional medications.

One idea that seemed to generate a lot of enthusiasm – perhaps as much due to the name that Patrik Brundin of the Van Andel Institute gave it – was the creation of a CIRM Hotel California, a place where researchers could go to learn new techniques, to share ideas, to collaborate and maybe take a nice cold drink by the pool (OK, I just made that last bit up to see if you were paying attention).

The meeting was remarkable not just for the flood of ideas, but also for its sense of collegiality.  Peter Marks, the director of the Food and Drug Administration’s Center for Biologics Evaluation and Research (FDA-CBER) captured that sense perfectly when he said the point of everyone working together, collaborating, sharing information and data, is to get these projects over the finish line. The more we work together, the more we will succeed.

A Month of CIRM: Where we’ve been, where we’re going

All this month we are using our blog and social media to highlight a new chapter in CIRM’s life, thanks to the voters approving Proposition 14. We are looking back at what we have done since we were created in 2004, and also looking forward to the future. We kick off this event with a letter from our the Chair of our Board, Jonathan Thomas.

When voters approved Proposition 14 last November, they gave the Stem Cell Agency a new lease on life and a chance to finish the work we began with the approval of Proposition 71 in 2004. It’s a great honor and privilege. It’s also a great responsibility. But I think looking back at what we have achieved over the last 16 years shows we are well positioned to seize the moment and take CIRM and regenerative medicine to the next level and beyond.

When we started, we were told that if we managed to get one project into a clinical trial by the time our money ran out we would have done a good job. As of this moment we have 68 clinical trials that we have funded plus another 31 projects in clinical trials where we helped fund crucial early stage research. That inexorable march to therapies and cures will resume when we take up our first round of Clinical applications under Prop 14 in March.

But while clinical stage projects are the end game, where we see if therapies really work and are safe in people, there’s so much more that we have achieved since we were created. We have invested $900 million in  basic research, creating a pipeline of the most promising stem cell research programs, as well as investing heavily on so-called “translational” projects, which move projects from basic science to where they’re ready to apply to the Food and Drug Administration (FDA) to begin clinical trials.

We have funded more than 1,000 projects, with each one giving us valuable information to help advance the science. Our funding has helped attract some of the best stem cell scientists in the world to California and, because we only fund research in California, it has persuaded many companies to either move here or open offices here to be eligible for our support. We have helped create the Alpha Stem Cell Clinics, a network of leading medical centers around the state that have the experience and expertise to deliver stem cell therapies to patients. All of those have made California a global center in the field.

That result is producing big benefits for the state. An independent Economic Impact Analysis reported that by the end of 2018 we had already helped generate an extra $10.7 billion in new sales revenue and taxes for California, hundreds of millions more in federal taxes and created more than 56,000 new jobs.

As if that wasn’t enough, we have also:

  • Helped develop the largest iPSC research bank in the world.
  • Created the CIRM Center of Excellence in Stem Cell Genomics to accelerate fundamental understanding of human biology and disease mechanisms.
  • Helped fund the construction of 12 world class stem cell institutes throughout the state.
  • Reached a unique partnership with the National Heart, Lung and Blood Institutes to find a cure for sickle cell disease.
  • Used our support for stem cell research to leverage an additional $12 billion in private funding for the field.
  • Enrolled more than 2700 patients in CIRM funded clinical trials

In many ways our work is just beginning. We have laid the groundwork, helped enable an extraordinary community of researchers and dramatically accelerated the field. Now we want to get those therapies (and many more) over the finish line and get them approved by the FDA so they can become available to many more people around the state, the country and the world.

We also know that we have to make these therapies available to all people, regardless of their background and ability to pay. We have to ensure that underserved communities, who were often left out of research in the past, are an integral part of this work and are included in every aspect of that research, particularly clinical trials. That’s why we now require anyone applying to us for funding to commit to engaging with underserved communities and to have a written plan to show how they are going to do that.

Over the coming month, you will hear more about some of the remarkable things we have managed to achieve so far and get a better sense of what we hope to do in the future. We know there will be challenges ahead and that not everything we do or support will work. But we also know that with the team we have built at CIRM, the brilliant research community in California and the passion and drive of the patient advocate community we will live up to the responsibility the people of California placed in us when they approved Proposition 14.

Inspiring new documentary about stem cell research

Poster for the documentary “Ending Disease”

2020 has been, to say the very least, a difficult and challenging year for all of us. But while the focus of the world has, understandably, been on the coronavirus there was also some really promising advances in stem cell research. Those advances are captured in a great new documentary called Ending Disease.

The documentary is by Emmy award-winning filmmaker Joe Gantz. In it he follows ten people who are facing life-threatening or life-changing diseases and injuries and who turn to pioneering stem cell therapies for help.

It’s an inspiring documentary, one that reminds you of the real need for new treatments and the tremendous hope and promise of stem cell therapies. Here’s a look at a trailer for Ending Disease.

You can see an exclusive screening of Ending Disease on Friday, January 8th, 2021 at 5:00pm PST.

After the livestream, there will be a live Q&A session where former members of the successful Proposition 14 campaign team – which refunded CIRM with an additional $5.5 billion – will be joined by CIRM’s President and CEO Dr. Maria Millan, talking about what lies ahead for CIRM and the future of stem cell research.

To purchase a ticket, click here. It only costs $12 and 50% of the ticket sales proceeds will go to Americans for Cures to help them continue to advocate for the advancement of stem cell research, and more importantly, for the patients and families to whom stem cell research provides so much hope.

If you need any extra persuading that it’s something you should definitely put on our calendar, here’s a letter from the film maker Joe Gantz.

I am the director of the documentary Ending Disease: The Stem Cell, Anti-Cancer T-Cell, & Antibody Revolution In Medicine, a film that will help inform people about the progress that’s been made in this field and how people with their lives on the line are now able to benefit from these new regenerative therapies. 

I was granted unprecedented access to ten of the first generation of clinical trials using stem cell and regenerative medicine to treat and cure many of the most devastating diseases and conditions including: brain cancer, breast cancer, leukemia and lymphoma, HIV, repairing a broken spinal cord, retinitis pigmentosa and SCID. The results are truly inspiring.

This is personal for me.  After spending four years making this documentary, I was diagnosed with bladder cancer. Upon diagnosis, I immediately felt the same desperation as millions of families who are in search of a medical breakthrough. I understood, on a personal level, what the patients we followed in the film all knew: when you are diagnosed with a disease, there is a narrow window of time in which you can effectively seek a life-saving treatment or cure. If treatment becomes available outside of that window, then it is too late. However, Ending Disease shows that with continued support for regenerative medicine, we can create a near future in which one-time cures and highly mitigating therapies are available to patients for a whole host of diseases.

Best regards,

Joe

“Mini-brains” model an autism spectrum disorder and help test treatments

Alysson Muotri, PhD, professor and director of the Stem Cell Program at UC San Diego School of Medicine
and member of the Sanford Consortium for Regenerative Medicine.
Image credit: UC San Diego Health

Rett syndrome is a rare form of autism spectrum disorder that impairs brain development and causes problems with movement, speech, and even breathing. It is caused by mutations in a gene called MECP2 and primarily affects females. Although there are therapies to alleviate symptoms, there is currently no cure for this genetic disorder.

With CIRM funding ($1.37M and $1.65M awards), Alysson Muotri, PhD and a team of researchers at the University of California San Diego School of Medicine and Sanford Consortium for Regenerative Medicine have used brain organoids that mimic Rett syndrome to identify two drug candidates that returned the “mini-brains” to near-normal. The drugs restored calcium levels, neurotransmitter production, and electrical impulse activity.

Brain organoids, also referred to as “mini-brains”, are 3D models made of cells that can be used to analyze certain features of the human brain. Although they are far from perfect replicas, they can be used to study changes in physical structure or gene expression over time.

Dr. Muotri and his team created induced pluripotent stem cells (iPSCs), a type of stem cell that can become virtually any type of cell. For the purposes of this study, they were created from the skin cells of Rett syndrome patients. The newly created iPSCs were then turned into brain cells and used to create “mini-brains”, thereby preserving each Rett syndrome patient’s genetic background. In addition to this, the team also created “mini-brains” that artificially lack the MECP2 gene, mimicking the issues with the same gene observed in Rett syndrome.

Lack of the MECP2 gene changed many things about the “mini-brains” such as shape, neuron subtypes present, gene expression patterns, neurotransmitter production, and decreases in calcium activity and electrical impulses. These changes led to major defects in the emergence of brainwaves.

To correct the changes caused by the lack of the MECP2 gene, the team treated the brain organoids with 14 different drug candidates known to affect various brain cell functions. Of all the drugs tested, two stood out: nefiracetam and PHA 543613. The two drugs resolved nearly all molecular and cellular symptoms observed in the Rett syndrome “mini-brains”, with the number active neurons doubling post treatment.

The two drugs were previously tested in clinical trials for the treatment of other conditions, meaning they have been shown to be safe for human consumption.

In a news release from UC San Diego Health, Dr. Muotri stresses that although the results for the two drugs are promising, the end treatment for Rett syndrome may require a multi-drug cocktail of sorts.

“There’s a tendency in the neuroscience field to look for highly specific drugs that hit exact targets, and to use a single drug for a complex disease. But we don’t do that for many other complex disorders, where multi-pronged treatments are used. Likewise, here no one target fixed all the problems. We need to start thinking in terms of drug cocktails, as have been successful in treating HIV and cancers.”

The full results of this study were published in EMBO Molecular Medicine.

Positive results from CIRM-funded LAD-I trial presented at the 62nd American Society of Hematology Annual Meeting

Gaurav Shah, M.D., CEO and President of Rocket Pharmaceuticals

Leukocyte Adhesion Deficiency-I (LAD-I) is a rare pediatric disease caused by a mutation in a specific gene that causes low levels of a protein called CD18. Due to low levels of CD18, the adhesion of immune cells is affected, which negatively impacts the body’s ability to combat infections.

Rocket Pharmaceuticals is conducting a CIRM-funded ($6.56 M) clinical trial that is testing a treatment that uses a gene therapy called RP-L201. The therapy uses a patient’s own blood stem cells and inserts a functional version of the gene.  These modified stem cells are then reintroduced back into the patient. The goal is to establish functional immune cells, enabling the body to combat infections. Previous studies have indicated that an increase in CD18 to 4-10% is associated with survival into adulthood. 

The company presented interim data from the trial at the 62nd American Society of Hematology (ASH) Annual Meeting in the form of an oral presentation. The data presented is from three pediatric patients with severe LAD-I, which is defined by CD18 expression of less than 2%. The patients were all treated with RP-L201. Patient One was 9-years of age at enrollment and had been followed for 12-months as of a cutoff date of November 2020. Patient Two was 3-years of age at enrollment and had been followed for over 6-months. Patient Three was 7-months of age at enrollment and was recently treated with RP-L201.

Key highlights from the presentation include:

  • RP-L201 was well tolerated, no safety issues reported with infusion or post-treatment
  • All patients achieved hematopoietic (blood) reconstitution within 5-weeks
    • 12 months post-treatment, Patient One demonstrated durable CD18 expression of approximately 40%,
    • 6-months post-treatment, Patient Two demonstrated CD18 expression of 23%
    • 2-months post-treatment, Patient Three demonstrated CD18 expression of 76%

In a press release from Rocket, Gaurav Shah, M.D., CEO and President of Rocket, expressed excitement about these results.

“…we continue to see encouraging evidence of efficacy for RP-L201 for the treatment of LAD-I. Patients have shown sustained CD18 expression of 23% to 40%, far exceeding the 4-10% threshold associated with survival into adulthood…”

To view the presentations at the conclusion of the oral presentation, click the link here.

CIRM Board Approves Four New Clinical Trials

A breakdown of CIRM’s clinical trials by disease area

This past Thursday the governing Board of the California Institute for Regenerative Medicine (CIRM) approved four new clinical trials in addition to ten new discovery research awards.

These new awards bring the total number of CIRM-funded clinical trials to 68.  Additionally, these new additions have allowed the state agency to exceed the goal of commencing 50 new trials outlined in its five year strategic plan.

$8,970,732 was awarded to Dr. Steven Deeks at the University of California San Francisco (UCSF) to conduct a clinical trial that modifies a patient’s own immune cells in order to treat and potentially cure HIV. 

Current treatment of HIV involves the use of long-term antiretroviral therapy (ART).  However, many people are not able to access and adhere to long-term ART.

Dr. Deeks and his team will take a patient’s blood and extract T cells, a type of immune cell.  The T cells are then genetically modified to express two different chimeric antigen receptors (CAR), which enable the newly created duoCAR-T cells to recognize and destroy HIV infected cells.  The modified T cells are then reintroduced back into the patient.

The goal of this one time therapy is to act as a long-term control of HIV with patients no longer needing to take ART, in effect a form of HIV cure.  This approach would also address the needs of those who are not able to respond to current approaches, which is estimated to be 50% of those affected by HIV globally. 

$3,728,485 was awarded to Dr. Gayatri Rao from Rocket Pharmaceuticals to conduct a clinical trial using a gene therapy for infantile malignant osteopetrosis (IMO), a rare and life-threatening disorder that develops in infancy.  IMO is caused by defective bone cell function, which results in blindness, deafness, bone marrow failure, and death very early in life. 

The trial will use a gene therapy that targets IMO caused by mutations in the TCIRG1 gene.  The team will take a young child’s own blood stem cells and inserting a functional version of the TCIRG1 gene.  The newly corrected blood stem cells are then introduced back into the child, with the hope of halting or preventing the progression of IMO in young children before much damage can occur. 

Rocket Pharmaceuticals has used the same gene therapy approach for modifying blood stem cells in a separate CIRM funded trial for a rare pediatric disease, which has shown promising results.

$8,996,474 was awarded to Dr. Diana Farmer at UC Davis to conduct a clinical trial of in utero repair of myelomeningocele (MMC), the most severe form of spina bifida.  MMC is a birth defect that occurs due to incomplete closure of the developing spinal cord, resulting in neurological damage to the exposed cord.  This damage leads to lifelong lower body paralysis, and bladder and bowel dysfunction.

Dr. Farmer and her team will use placenta tissue to generate mesenchymal stem cells (MSCs).  The newly generated MSCs will be seeded onto an FDA approved dural graft and the product will be applied to the spinal cord while the infant is still developing in the womb.  The goal of this therapy is to help promote proper spinal cord formation and improve motor function, bladder function, and bowel function. 

The clinical trial builds upon the work of CIRM funded preclinical research.

$8,333,581 was awarded to Dr. David Williams at Boston Children’s Hospital to conduct a gene therapy clinical trial for sickle cell disease (SCD).  This is the second project that is part of an agreement between CIRM and the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health, to co-fund cell and gene therapy programs under the NHLBI’s  “Cure Sickle Cell” Initiative.  The goal of this agreement is to markedly accelerate clinical development of cell and gene therapies to cure SCD.

SCD is an inherited disease caused by a single gene mutation resulting in abnormal hemoglobin, which causes red blood cells to ‘sickle’ in shape.  Sickling of red blood cells clogs blood vessels and leads to progressive organ damage, pain crises, reduced quality of life, and early death. 

The team will take a patient’s own blood stem cells and insert a novel engineered gene to silence abnormal hemoglobin and induce normal fetal hemoglobin expression.  The modified blood stem cells will then be reintroduced back into the patient.  The goal of this therapy is to aid in the production of normal shaped red blood cells, thereby reducing the severity of the disease.

“Today is a momentus occasion as CIRM reaches 51 new clinical trials, surpassing one of the goals outlined in its five year strategic plan,” says Maria T. Millan, M.D., President and CEO of CIRM.  “These four new trials, which implement innovative approaches in the field of regenerative medicine, reflect CIRM’s ever expanding and diverse clinical portfolio.”

The Board also approved ten awards that are part of CIRM’s Quest Awards Prgoram (DISC2), which promote promising new technologies that could be translated to enable broad use and improve patient care.

The awards are summarized in the table below:

  APPLICATION  TITLE  INSTITUTION  AWARD AMOUNT  
    DISC2-12169  Human-induced pluripotent stem cell-derived glial enriched progenitors to treat white matter stroke and vascular dementia.  UCLA  $250,000
  DISC2-12170Development of COVID-19 Antiviral Therapy Using Human iPSC-Derived Lung Organoids  UC San Diego  $250,000
  DISC2-12111Hematopoietic Stem Cell Gene Therapy for X-linked Agammaglobulinemia  UCLA  $250,000
  DISC2-12158Development of a SYF2 antisense oligonucleotide (ASO) treatment for ALSUniversity of Southern California  $249,997
    DISC2-12124Dual angiogenic and immunomodulating nanotechnology for subcutaneous stem cell derived islet transplantation for the treatment of diabetes  Lundquist Institute  $250,000
  DISC2-12105Human iPSC-derived chimeric antigen receptor-expressing macrophages for cancer treatment  UC San Diego  $250,000
  DISC2-12164Optimization of a human interneuron cell therapy for traumatic brain injury  UC Irvine  $250,000
  DISC2-12172Combating COVID-19 using human PSC-derived NK cells  City of Hope  $249,998
  DISC2-12126The First Orally Delivered Cell Therapy for the Treatment of Inflammatory Bowel Disease  Vitabolus Inc.  $249,000
    DISC2-12130Transplantation of Pluripotent Stem Cell Derived Microglia for the Treatment of Adult-onset Leukoencephalopathy (HDLS/ALSP)  UC Irvine  $249,968

CIRM-funded development of stem cell therapy for Canavan disease shows promising results

Yanhong Shi, Ph.D., City of Hope

Canavan disease is a fatal neurological disorder, the most prevalent form of which begins in infancy. It is caused by mutation of the ASPA gene, resulting in the deterioration of white matter (myelin) in the brain and preventing the proper transmission of nerve signals.  The mutated ASPA gene causes the buildup of an amino acid called NAA and is typically found in neurons in the brain.  As a result of the NAA buildup, Canavan disease causes symptoms such as impaired motor function, mental retardation, and early death. Currently, there is no cure or standard of treatment for this condition.

Fortunately, CIRM-funded research conducted at City of Hope by Yanhong Shi, Ph.D. is developing a stem cell-based treatment for Canavan disease. The research is part of CIRM’s Translational Stage Research Program, which promotes the activities necessary for advancement to clinical study of a potential therapy.

The results from the study are promising, with the therapy improving motor function, reducing degeneration of various brain regions, and expanding lifespan in a Canavan disease mouse model.

For this study, induced pluripotent stem cells (iPSCs), which can turn into virtually any type of cells, were created from skin cells of Canavan disease patients. The newly created iPSCs were then used to create neural progenitor cells (NPCs), which have the ability to turn into various types of neural cells in the central nervous system. A functional version of the ASPA gene was then introduced into the NPCs. These newly created NPCs were then transplanted inside the brains of Canavan disease mice.

The study also used iPSCs engineered to have a functional version of the ASPA gene. The genetically modified iPSCs were then used to create oligodendrocyte progenitor cells (OPCs), which have the ability to turn into myelin. The OPCs were also transplanted inside the brains of mice.

The rationale for evaluating both NPCs and OPCs was that NPCs typically stayed at the site of injection while OPCs tend to migrate, which might have been important in terms of the effectiveness of the therapy.  However, the results of the study show that both NPCs and OPCs were effective, with both being able to reduce levels of NAA, presumably because NAA can move to where the ASPA enzyme is although NPCs do not migrate.  This resulted in improved motor function, recovery of myelin, and reduction of brain degeneration, in both the NPC and OPC-transplanted Canavan disease mice.

“Thanks to funding from CIRM and the hard work of my team here at City of Hope and collaborators at Center for Biomedicine and Genetics, Department of Molecular Imaging and Therapy, and Diabetes and Metabolism Institute at City of Hope, as well as collaborators from the University of Texas Medical Branch at Galveston, University of Rochester Medical Center, and Aarhus University, we were able to carry out this study which has demonstrated promising results,” said Dr. Shi.  “I hope that these findings can one day bring about an effective therapy for Canavan disease patients, who currently have no treatment options.”

Dr. Shi and her team will build on this research by starting IND-enabling studies using their NPC therapy soon.  This is the final step in securing approval from the Food and Drug Administration (FDA) in order to test the therapy in patients.  

The full study was published in Advanced Science.