leslie thompson

Building a progressive pipeline

/ Kevin McCormack / Leave a comment
Dr. Kelly Shepard

By Dr. Kelly Shepard

One of our favorite things to do at CIRM is deliver exciting news about CIRM projects. This usually entails discussion of recent discoveries that made headlines, or announcing the launch of a new CIRM-funded clinical trial …. tangible signs of progress towards addressing unmet medical needs through advances in stem technology.

But there are equally exciting signs of progress that are not always so obvious to the untrained eye-  those that we are privileged to witness behind the scenes at CIRM. These efforts don’t always lead to a splashy news article or even to a scientific publication, but they nonetheless drive the evolution of new ideas and can help steer the field away from futile lines of investigation. Dozens of such projects are navigating uncharted waters by filling knowledge gaps, breaking down technical barriers, and working closely with regulatory agencies to define novel and safe paths to the clinic.

These efforts can remain “hidden” because they are in the intermediate stages of the long, arduous and expensive journey from “bench to beside”.  For the pioneering projects that CIRM funds, this journey is unique and untrod, and can be fraught with false starts. But CIRM has developed tools to track the momentum of these programs and provide continuous support for those with the most promise. In so doing, we have watched projects evolve as they wend their way to the clinic. We wanted to share a few examples of how we do this with our readers, but first… a little background for our friends who are unfamiliar with the nuts and bolts of inventing new medicines.

A common metaphor for bringing scientific discoveries to market is a pipeline, which begins in a laboratory where a discovery occurs, and ends with government approval to commercialize a new medicine, after it is proven to be safe and effective. In between discovery and approval is a stage called “Translation”, where investigators develop ways to transition their “research level” processes to “clinically compatible” ones, which only utilize substances that are of certified quality for human use. 

Investigators must also work out novel ways to manufacture the product at larger scale and transition the methods used for testing in animal models to those that can be implemented in human subjects.

A key milestone in Translation is the “preIND” (pre Investigational New Drug (IND) meeting, where an investigator presents data and plans to the US Food and Drug Administration (FDA) for feedback before next stage of development begins, the pivotal testing needed to show it is both safe and effective.

These “IND enabling studies” are rigorous but necessary to support an application for an IND and the initiation of clinical trials, beginning with phase 1 to assess safety in a small number of individuals, and phase 2, where an expanded group is evaluated to see if the therapy has any benefits for the patient. Phase 3 trials are studies of very large numbers of individuals to gain definitive evidence of safety and therapeutic effect, generally the last step before applying to the FDA for market approval. An image of the pipeline and the stages described are provided in our diagram below.

The pipeline can be notoriously long and tricky, with plenty of twists, turns, and unexpected obstacles along the way. Many more projects enter than emerge from this gauntlet, but as we see from these examples of ‘works in progress”, there is a lot of momentum building.

Caption for Graphic: This graphic shows the number of CIRM-funded projects and the stages they have progressed through multiple rounds of CIRM funding. For example, the topmost arrow shows that are about 19 projects at the translational stage of the pipeline that received earlier support through one of CIRM’s Discovery stage programs. Many of these efforts came out of our pre-2016 funding initiatives such as Early Translation, Basic Biology and New Faculty Awards. In another example, you can see that about 15 awards that were first funded by CIRM at the IND enabling stage have since progressed into a phase 1 or phase 2 clinical trials. While most of these efforts also originated in some of CIRM’s pre-2016 initiatives such as the Disease Team Awards, others have already progressed from CIRM’s newer programs that were launched as part of the “2.0” overhaul in 2016 (CLIN1).

The number of CIRM projects that have evolved and made their way down the pipeline with CIRM support is impressive, but it is clearly an under-representation, as there are other projects that have progressed outside of CIRM’s purview, which can make things trickier to verify.

We also track projects that have spun off or been licensed to commercial organizations, another very exciting form of “progression”. Perhaps those will contribute to another blog for another day! In the meantime, here are a just a few examples of some of the progressors that are depicted on the graphic.

Project: stem cell therapy to enhance bone healing in the elderly

– Currently funded stage: IND enabling development, CLIN1-11256 (Dr. Zhu, Ankasa Regenerative Therapeutics)

– Preceded by preIND-enabling studies, TRAN1-09270 (Dr. Zhu, Ankasa Regenerative Therapeutics)

– Preceded by discovery stage research grant TR1-01249 (Dr. Longaker and Dr. Helm, Stanford)

Project: embryonic stem cell derived neural cell therapy for Huntington Disease

– Currently funded stage: IND enabling development, CLIN1-10953 (Dr. Thompson, UC Irvine)

– Preceded by preIND-enabling studies, PC1-08117 (Dr. Thompson, UC Irvine)

– Preceded by discovery stage research grant (TR2-01841) (Dr. Thompson, UC Irvine)

Project: gene-modified hematopoietic stem cells for Artemis Deficient severe combined immunodeficiency (SCID)

– Currently funded stage: Phase 1 clinical trial CLIN2-10830 (Dr. Cowan, UC San Francisco)

– Preceded by IND enabling development, CLIN1-08363 (Dr. Puck, UC San Francisco)

– Preceded by discovery stage research grant, TR3-05535  (Dr. Cowan, UC San Francisco)

Project: retinal progenitor cell therapy for retinitis pigmentosa

– Currently funded stage: Phase 2 and 2b clinical trials, CLIN2-11472, CLIN2-09698 (Dr. Klassen, JCyte, Inc.)

– Preceded by IND enabling development, DR2A-05739 (Dr. Klassen, UC Irvine)

– Preceded by discovery stage research grant, TR2-01794 (Dr. Klassen, UC Irvine)

A Tribute to Huntington’s Disease Warriors in the Age of COVID-19

/ Kevin McCormack / Leave a comment

Frances Saldana is one of the most remarkable women I know. She has lost all three of her children to Huntington’s disease (HD) – a nasty, fatal disease that steadily destroys the nerve cells in the brain – but still retains a fighting spirit and a commitment to finding a cure for HD. She is the President Emeritus for HD-Care, an organization dedicated to raising awareness about HD, and finding money for research to cure it. She recently wrote a Mother’s Day blog for HD-Care about the similarities between HD and COVID-19. As May is National Huntington’s Disease Awareness Month we wanted to share her blog with you.

Frances Saldana

COVID-19 has consumed our entire lives, and for many, our livelihoods.  This is a pandemic like we have never experienced in our lifetime, bringing out in many families fear, financial devastation, disabilities, isolation, suffering, and worst of all, loss of life.  But through all this, the pandemic has uncovered emotions in many who rose to the occasion – a fight and stamina beyond human belief.

As a family member who has lost all of my children to Huntington’s disease, it makes me so sad to watch and hear about the suffering that people all over the world are currently experiencing with COVID-19.  This devastation is nothing new to Huntington’s disease families.  Although Huntington’s disease (HD) is not contagious, it is genetic, and much of the uncertainty and fears that families are experiencing are so similar to what HD families experience….in slow motion, with unanswered questions such as:  

  • Who in my family is carrying the mutant HD gene?  (Who in my family is carrying the coronavirus?)
  • Who in my family will inherit the mutant HD gene? (Who will get infected by the COVID-19?)
  • Will my loved on live long enough to benefit from a treatment for HD? (Will there be a vaccination soon if my loved one is infected by COVID-19?) 
  • How long will my HD family member live?  (Will my affected COVID-19 loved one survive after being placed on a ventilator?)
  • Is my HD family member going to die?  (Will my COVID-19 family member die?)

In watching some of the footage of COVID-19 patients on TV and learning about the symptoms, it appears that those with a severe case of the virus go through similar symptoms as HD patients who are in the late and end-of-life stages:  pneumonia, sepsis, pain, and suffering, to name a few, although for HD families, the journey goes on for years or even decades, and then carries on to the next generation, and not one HD patient will survive the disease. Not yet!

Scientists are working furiously all over the world to find a treatment for COVID-19.  The same goes for scientists focused on Huntington’s disease research.  Without their brilliant work we would have no hope.  Without funding there would be no science.  I have been saying for the last 20 years that we will have a treatment for Huntington’s disease in the next couple of years, but with actual facts and successful clinical trials, there is finally a light at the end of the tunnel and we have much to be thankful for.  I feel it in my heart that a treatment will be found for both COVID-19 and Huntington’s disease very soon.    

The month of May happens to be National Huntington’s Disease Awareness Month.  Mother’s Day also falls in the month of May.  Huntington’s disease “Warrior Moms” are exemplary women, and I have been blessed to have known a few.  Driven by love for their children, they’ve worn many hats as caregivers, volunteers, and HD community leaders in organizations such as HD-CARE, HDSA, WeHaveAFace, Help4HD, HD Support &Care Network, and many others. 

The mothers have often also been forced to take on the role of breadwinners when the father of the family has unexpectedly become debilitated from HD.   In spite of carrying a heavy cross, HD Warrior Moms persevere, and they do it with endless love, often taking care of HD family members from one generation to the next.  They are the front-line workers in the HD community, tirelessly protecting their families and at the same time doing all they can to provide a meaningful quality of life. 

Many HD Warrior moms have lost their children in spite of their fierce fight to save them, but they keep their memory alive, never losing hope for a treatment that will end the pain, suffering, and loss of life. Many HD Warrior Moms have lost the fight themselves, not from HD, but from a broken heart. These are the HD Warrior Moms.

We salute them all. We love them all.

CIRM is funding several projects targeting HD. You can read about them here.

Rare Disease Gets Big Boost from California’s Stem Cell Agency

/ Kevin McCormack / 4 Comments
UC Irvine’s Dr. Leslie Thompson and patient advocate Frances Saldana after the CIRM Board vote to approve funding for Huntington’s disease

If you were looking for a poster child for an unmet medical need Huntington’s disease (HD) would be high on the list. It’s a devastating disease that attacks the brain, steadily destroying the ability to control body movement and speech. It impairs thinking and often leads to dementia. It’s always fatal and there are no treatments that can stop or reverse the course of the disease. Today the Board of the California Institute for Regenerative Medicine (CIRM) voted to support a project that shows promise in changing that.

The Board voted to approve $6 million to enable Dr. Leslie Thompson and her team at the University of California, Irvine to do the late stage testing needed to apply to the US Food and Drug Administration for permission to start a clinical trial in people. The therapy involves transplanting stem cells that have been turned into neural stem cells which secrete a molecule called brain-derived neurotrophic factor (BDNF), which has been shown to promote the growth and improve the function of brain cells. The goal is to slow down the progression of this debilitating disease.

“Huntington’s disease affects around 30,000 people in the US and children born to parents with HD have a 50/50 chance of getting the disease themselves,” says Dr. Maria T. Millan, the President and CEO of CIRM. “We have supported Dr. Thompson’s work for a number of years, reflecting our commitment to helping the best science advance, and are hopeful today’s vote will take it a crucial step closer to a clinical trial.”

Another project supported by CIRM at an earlier stage of research was also given funding for a clinical trial.

The Board approved almost $12 million to support a clinical trial to help people undergoing a kidney transplant. Right now, there are around 100,000 people in the US waiting to get a kidney transplant. Even those fortunate enough to get one face a lifetime on immunosuppressive drugs to stop the body rejecting the new organ, drugs that increase the risk for infection, heart disease and diabetes.  

Dr. Everett Meyer, and his team at Stanford University, will use a combination of healthy donor stem cells and the patient’s own regulatory T cells (Tregs), to train the patient’s immune system to accept the transplanted kidney and eliminate the need for immunosuppressive drugs.

The initial group targeted in this clinical trial are people with what are called HLA-mismatched kidneys. This is where the donor and recipient do not share the same human leukocyte antigens (HLAs), proteins located on the surface of immune cells and other cells in the body. Around 50 percent of patients with HLA-mismatched transplants experience rejection of the organ.

In his application Dr. Meyer said they have a simple goal: “The goal is “one kidney for life” off drugs with safety for all patients. The overall health status of patients off immunosuppressive drugs will improve due to reduction in side effects associated with these drugs, and due to reduced graft loss afforded by tolerance induction that will prevent chronic rejection.”

Stem cell-derived blood-brain barrier gives more complete picture of Huntington’s disease

/ Todd Dubnicoff / Leave a comment

Like a sophisticated security fence, our bodies have evolved a barrier that protects the brain from potentially harmful substances in the blood but still allows the entry of essential molecules like blood sugar and oxygen. Just like in other parts of the body, the blood vessels and capillaries in the brain are lined with endothelial cells. But in the brain, these cells form extremely tight connections with each other making it nearly impossible for most things to passively squeeze through the blood vessel wall and into the brain fluid.

BloodBrainBarrier

Compared to blood vessels in other parts of the body, brain blood vessels form a much tighter seal to protect the brain.
Image source: Dana and Chris Reeve Foundation

Recent studies have shown defects in the brain-blood barrier are associated with neurodegenerative disorders like Huntington’s disease and as a result becomes leakier. Although the debilitating symptoms of Huntington’s disease – which include involuntary movements, severe mood swings and difficulty swallowing – are primarily due to the gradual death of specific nerve cells, this breakdown in the blood-brain barrier most likely contributes to the deterioration of the Huntington’s brain.

What hasn’t been clear is if mutations in Huntingtin, the gene that is linked to Huntington’s disease, directly impact the specialized endothelial cells within the blood-brain barrier or if these specialized cells are just innocent bystanders of the destruction that occurs as Huntington’s progresses. It’s an important question to answer. If the mutations in Huntingtin directly affect the blood-brain barrier then it could provide a bigger picture of how this incurable, fatal disease works. More importantly, it may provide new avenues for therapy development.

A UC Irvine research team got to the bottom of this question with the help of induced pluripotent stem cells (iPSCs) derived from the skin cells of individuals with Huntington’s disease. Their CIRM-funded study was published this week in Cell Reports.

In a first for a neurodegenerative disease, the researchers coaxed the Huntington’s disease iPSCs in a lab dish to become brain microvascular endothelial cells (BMECs), the specialized cells responsible for forming the blood-brain barrier. The researchers found that the Huntington’s BMECs themselves were indeed dysfunctional. Compared to BMECs derived from unaffected individuals, the Huntington’s BMECs weren’t as good at making new blood vessels, and the vessels they did make were leakier. So the Huntingtin mutation in these BMECs appears to be directly responsible for the faulty blood-brain barrier.

The team dug deeper into this new insight by looking for possible differences in gene activity between the healthy and Huntington’s BMECs. They found that the Wnt group of genes, which plays an important role in the development of the blood-brain barrier, are over active in the Huntington’s BMECs. This altered Wnt activity can explain the leaky defects. In fact, the use of a drug inhibitor of Wnt fixed the defects. Dr. Leslie Thompson, the team lead, described the significance of this finding in a press release:

“Now we know there are internal problems with blood vessels in the brain. This discovery can be used for possible future treatments to seal the leaky blood vessels themselves and to evaluate drug delivery to patients with HD.”

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Study leader, Leslie Thompson. Steve Zylius / UCI

A companion Cell Stem Cell report, also published this week, used the same iPSC-derived blood-brain barrier system. In that study, researchers at Cedars-Sinai pinpointed BMEC defects as the underlying cause of Allan-Herndon-Dudley syndrome, another neurologic condition that causes mental deficits and movement problems. Together these results really drive home the importance of studying the blood-brain barrier function in neurodegenerative disease.

Dr. Ryan Lim, the first author on the UC Irvine study, also points to a larger perspective on the implications of this work:

“These studies together demonstrate the incredible power of iPSCs to help us more fully understand human disease and identify the underlying causes of cellular processes that are altered.”