Rare Disease, Type 1 Diabetes, and Heart Function: Breakthroughs for Three CIRM-Funded Studies

This past week, there has been a lot of mention of CIRM funded studies that really highlight the importance of the work we support and the different disease areas we make an impact on. This includes important research related to rare disease, Type 1 Diabetes (T1D), and heart function. Below is a summary of the promising CIRM-funded studies released this past week for each one of these areas.

Rare Disease

Comparison of normal (left) and Pelizaeus-Merzbacher disease (PMD) brains (right) at age 2. 

Pelizaeus-Merzbacher disease (PMD) is a rare genetic condition affecting boys. It can be fatal before 10 years of age and symptoms of the disease include weakness and breathing difficulties. PMD is caused by a disruption in the formation of myelin, a type of insulation around nerve fibers that allows electrical signals in the brain to travel quickly. Without proper signaling, the brain has difficulty communicating with the rest of the body. Despite knowing what causes PMD, it has been difficult to understand why there is a disruption of myelin formation in the first place.

However, in a CIRM-funded study, Dr. David Rowitch, alongside a team of researchers at UCSF, Stanford, and the University of Cambridge, has been developing potential stem cell therapies to reverse or prevent myelin loss in PMD patients.

Two new studies, of which Dr. Rowitch is the primary author, published in Cell Stem Cell, and Stem Cell Reports, respectively report promising progress in using stem cells derived from patients to identify novel PMD drugs and in efforts to treat the disease by directly transplanting neural stem cells into patients’ brains. 

In a UCSF press release, Dr. Rowitch talks about the implications of his findings, stating that,

“Together these studies advance the field of stem cell medicine by showing how a drug therapy could benefit myelination and also that neural stem cell transplantation directly into the brains of boys with PMD is safe.”

Type 1 Diabetes

Viacyte, a company that is developing a treatment for Type 1 Diabetes (T1D), announced in a press release that the company presented preliminary data from a CIRM-funded clinical trial that shows promising results. T1D is an autoimmune disease in which the body’s own immune system destroys the cells in the pancreas that make insulin, a hormone that enables our bodies to break down sugar in the blood. CIRM has been funding ViaCyte from it’s very earliest days, investing more than $72 million into the company.

The study uses pancreatic precursor cells, which are derived from stem cells, and implants them into patients in an encapsulation device. The preliminary data showed that the implanted cells, when effectively engrafted, are capable of producing circulating C-peptide, a biomarker for insulin, in patients with T1D. Optimization of the procedure needs to be explored further.

“This is encouraging news,” said Dr. Maria Millan, President and CEO of CIRM. “We are very aware of the major biologic and technical challenges of an implantable cell therapy for Type 1 Diabetes, so this early biologic signal in patients is an important step for the Viacyte program.”

Heart Function

Although various genome studies have uncovered over 500 genetic variants linked to heart function, such as irregular heart rhythms and heart rate, it has been unclear exactly how they influence heart function.

In a CIRM-funded study, Dr. Kelly Frazer and her team at UCSD studied this link further by deriving heart cells from induced pluripotent stem cells. These stem cells were in turn derived from skin samples of seven family members. After conducting extensive genome-wide analysis, the team discovered that many of these genetic variations influence heart function because they affect the binding of a protein called NKX2-5.

In a press release by UCSD, Dr. Frazer elaborated on the important role this protein plays by stating that,

“NKX2-5 binds to many different places in the genome near heart genes, so it makes sense that variation in the factor itself or the DNA to which it binds would affect that function. As a result, we are finding that multiple heart-related traits can share a common mechanism — in this case, differential binding of NKX2-5 due to DNA variants.”

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

“Brains” in a dish that can create electrical impulses

Brain organoids in a petri dish: photo courtesy UCSD

For several years, researchers have been able to take stem cells and use them to make three dimensional structures called organoids. These are a kind of mini organ that scientists can then use to study what happens in the real thing. For example, creating kidney organoids to see how kidney disease develops in patients.

Scientists can do the same with brain cells, creating clumps of cells that become a kind of miniature version of parts of the brain. These organoids can’t do any of the complex things our brains do – such as thinking – but they do serve as useful physical models for us to use in trying to develop a deeper understanding of the brain.

Now Alysson Muotri and his team at UC San Diego – in a study supported by two grants from CIRM – have taken the science one step further, developing brain organoids that allow us to measure the level of electrical activity they generate, and then compare it to the electrical activity seen in the developing brain of a fetus. That last sentence might cause some people to say “What?”, but this is actually really cool science that could help us gain a deeper understanding of how brains develop and come up with new ways to treat problems in the brain caused by faulty circuitry, such as autism or schizophrenia.

The team developed new, more effective methods of growing clusters of the different kinds of cells found in the brain. They then placed them on a multi-electrode array, a kind of muffin tray that could measure electrical impulses. As they fed the cells and increased the number of cells in the trays they were able to measure changes in the electrical impulses they gave off. The cells went from producing 3,000 spikes a minute to 300,000 spikes a minute. This is the first time this level of activity has been achieved in a cell-based laboratory model. But that’s not all.

When they further analyzed the activity of the organoids, they found there were some similarities to the activity seen in the brains of premature babies. For instance, both produced short bursts of activity, followed by a period of inactivity.

Alysson Muotri

In a news release Muotri says they were surprised by the finding:

“We couldn’t believe it at first — we thought our electrodes were malfunctioning. Because the data were so striking, I think many people were kind of skeptical about it, and understandably so.”

Muotri knows that this research – published in the journal Cell Stem Cell – raises ethical issues and he is quick to say that these organoids are nothing like a baby’s brain, that they differ in several critical ways. The organoids are tiny, not just in size but also in the numbers of cells involved. They also don’t have blood vessels to keep them alive or help them grow and they don’t have any ability to think.

“They are far from being functionally equivalent to a full cortex, even in a baby. In fact, we don’t yet have a way to even measure consciousness or sentience.”

What these organoids do have is the ability to help us look at the structure and activity of the brain in ways we never could before. In the past researchers depended on mice or other animals to test new ideas or therapies for human diseases or disorders. Because our brains are so different than animal brains those approaches have had limited results. Just think about how many treatments for Alzheimer’s looked promising in animal models but failed completely in people.

These new organoids allow us to explore how new therapies might work in the human brain, and hopefully increase our ability to develop more effective treatments for conditions as varied as epilepsy and autism.

CIRM Board Approves $19.7 Million in Awards for Translational Research Program

In addition to approving funding for breast cancer related brain metastases last week, the CIRM Board also approved an additional $19.7 million geared towards our 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.

Before getting into the details of each project, here is a table with a brief synopsis of the awards:

TRAN1 – 11532

Illustration of a healthy eye vs eye with AMD

$3.73 million was awarded to Dr. Mark Humayun at USC to develop a novel therapeutic product capable of slowing the progression of age-related macular degeneration (AMD).

AMD is an eye disease that causes severe vision impairment, resulting in the inability to read, drive, recognize faces, and blindness if left untreated.  It is the leading cause of vision loss in the U.S. and currently affects over 2 million Americans.  By the year 2050, it is projected that the number of affected individuals will more than double to over 5 million.  A layer of cells in the back of the eye called the retinal pigment epithelium (RPE) provide support to photoreceptors (PRs), specialized cells that play an important role in our ability to process images.  The dysfunction and/or loss of RPE cells plays a critical role in the loss of PRs and hence the vision problems observed in AMD.  One form of AMD is known as dry AMD (dAMD) and accounts for about 90% of all AMD cases.

The approach that Dr. Humayun is developing will use a biologic product produced by human embryonic stem cells (hESCs). This material will be injected into the eye of patients with early development of dAMD, supporting the survival of photoreceptors in the affected retina.

TRAN1 – 11579

Illustration depicting the role neuronal relays play in muscle sensation

$6.23 million was awarded to Dr. Mark Tuszynski at UCSD to develop a neural stem cell therapy for spinal cord injury (SCI).

According to data from the National Spinal Cord Injury Statistical Center, as of 2018, SCI affects an estimated 288,000 people in the United States alone, with about 17,700 new cases each year. There are currently no effective therapies for SCI. Many people suffer SCI in early adulthood, leading to life-long disability and suffering, extensive treatment needs and extremely high lifetime costs of health care.

The approach that Dr. Tuszynski is developing will use hESCs to create neural stem cells (NSCs).  These newly created NSCs would then be grafted at the site of injury of those with SCI.  In preclinical studies, the NSCs have been shown to support the formation of neuronal relays at the site of SCI.  The neuronal relays allow the sensory neurons in the brain to communicate with the motor neurons in the spinal cord to re-establish muscle control and movement.

TRAN1 – 11548

Graphic depicting the challenges of traumatic brain injury (TBI)

$4.83 million was awarded to Dr. Brian Cummings at UC Irvine to develop a neural stem cell therapy for traumatic brain injury (TBI).

TBI is caused by a bump, blow, or jolt to the head that disrupts the normal function of the brain, resulting in emotional, mental, movement, and memory problems. There are 1.7 million people in the United States experiencing a TBI that leads to hospitalization each year. Since there are no effective treatments, TBI is one of the most critical unmet medical needs based on the total number of those affected and on a cost basis.

The approach that Dr. Cummings is developing will also use hESCs to create NSCs.  These newly created NSCs would be integrated with injured tissue in patients and have the ability to turn into the three main cell types in the brain; neurons, astrocytes, and oligodendrocytes.  This would allow for TBI patients to potentially see improvements in issues related to memory, movement, and anxiety, increasing independence and lessening patient care needs.

TRAN1 – 11628

Illustration depicting the brain damage that occurs under hypoxic-ischemic conditions

$4.96 million was awarded to Dr. Evan Snyder at Sanford Burnham Prebys to develop a neural stem cell therapy for perinatal hypoxic-ischemic brain injury (HII).

HII occurs when there is a lack of oxygen flow to the brain.  A newborn infant’s body can compensate for brief periods of depleted oxygen, but if this lasts too long, brain tissue is destroyed, which can cause many issues such as developmental delay and motor impairment.  Current treatment for this condition is whole-body hypothermia (HT), which consists of significantly reducing body temperature to interrupt brain injury.  However, this is not very effective in severe cases of HII. 

The approach that Dr. Snyder is developing will use an established neural stem cell (NSC) line.   These NSCs would be injected and potentially used alongside HT treatment to increase protection from brain injury.

“A new awakening”: One patient advocate’s fight for her daughters life

We often talk about the important role that patient advocates play in helping advance research. That was demonstrated in a powerful way last week when the CIRM Board approved almost $12 million to fund a clinical trial targeting a rare childhood disorder called cystinosis.

The award, to Stephanie Cherqui and her team at UC San Diego (in collaboration with UCLA) was based on the scientific merits of the program. But without the help of the cystinosis patient advocate community that would never have happened. Years ago the community held a series of fundraisers, bake sales etc., and used the money to help Dr. Cherqui get her research started.

That money enabled Dr. Cherqui to get the data she needed to apply to CIRM for funding to do more detailed research, which led to her award last week. There to celebrate the moment was Nancy Stack. Her testimony to the Board was a moving celebration of how long they have worked to get to this moment, and how much hope this research is giving them.

Nancy Stack is pictured in spring 2018 with her daughter Natalie Stack and husband Geoffrey Stack. (Lar Wanberg/Cystinosis Research Foundation)

Hello my name is Nancy Stack and I am the founder and president of the Cystinosis Research Foundation.  Our daughter Natalie was diagnosed with cystinosis when she was an infant. 

Cystinosis is a rare disease that is characterized by the abnormal accumulation of cystine in every cell in the body.  The build-up of cystine eventually destroys every organ in the body including the kidneys, eyes, liver, muscles, thyroid and brain.  The average age of death from cystinosis and its complications is 28 years of age.

For our children and adults with cystinosis, there are no healthy days. They take between 8-12 medications around the clock every day just to stay alive – Natalie takes 45 pills a day.  It is a relentless and devastating disease.

Medical complications abound and our children’s lives are filled with a myriad of symptoms and treatments – there are g-tube feedings, kidney transplants, bone pain, daily vomiting,  swallowing difficulties, muscle wasting, severe gastrointestinal side effects and for some blindness.   

We started the Foundation in 2003.  We have worked with and funded Dr. Stephanie Cherqui since 2006.   As a foundation, our resources are limited but we were able to fund the initial grants for Stephanie’s  Stem Cell studies. When CIRM awarded a grant to Stephanie in 2016, it allowed her to complete the studies, file the IND and as a result, we now have FDA approval for the clinical trial. Your support has changed the course of this disease. 

When the FDA approved the clinical trial for cystinosis last year, our community was filled with a renewed sense of hope and optimism.  I heard from 32 adults with cystinosis – all of them interested in the clinical trial.  Our adults know that this is their only chance to live a full life. Without this treatment, they will die from cystinosis.  In every email I received, there was a message of hope and gratitude. 

I received an email from a young woman who said this, “It’s a new awakening to learn this morning that human clinical trials have been approved by the FDA. I reiterate my immense interest to participate in this trial as soon as possible because my quality of life is at a low ebb and the trial is really my only hope. Time is running out”. 

And a mom of a 19 year old young man who wants to be the first patient in the trial wrote and said this, “On the day the trial was announced I started to cry tears of pure happiness and I thought, a mother somewhere gets to wake up and have a child who will no longer have cystinosis. I felt so happy for whom ever that mom would be….I never imagined that the mom I was thinking about could be me. I am so humbled to have this opportunity for my son to try to live disease free.

My own daughter ran into my arms that day and we cried tears of joy – finally, the hope we had clung to was now a reality. We had come full circle.  I asked Natalie how it felt to know that she could be cured and she said, “I have spent my entire life thinking that I would die from cystinosis in my 30s but now, I might live a full life and I am thinking about how much that changes how I think about my future. I never planned too far ahead but now I can”. 

As a mother, words can’t possible convey what it feels like to know that my child has a chance to live a long, healthy life free of cystinosis – I can breathe again. On behalf of all the children and adults with cystinosis, thank you for funding Dr. Cherqui, for caring about our community, for valuing our children and for making this treatment a reality.  Our community is ready to start this trial – thank you for making this happen.

*************

CIRM will be celebrating the role of patient advocates at a free event in Los Angeles tomorrow. It’s at the LA Convention Center and here are the details. And did I mention it’s FREE!

Tue, June 25, 2019 – 6:00 PM – 7:00 PM PDT

Petree Hall C., Los Angeles Convention Center, 1201 South Figueroa Street Los Angeles, CA 90015

And on Wednesday, USC is holding an event highlighting the progress being made in fighting diseases that destroy vision. Here’s a link to information about the event.

Seeing is believing: A new tool to help us learn about stem cells.

Cave paintings from Libya: evidence humans communicated through visual images long before they created text

There’s a large body of research that shows that many people learn better through visuals. Studies show that much of the sensory cortex in our brain is devoted to vision so our brains use images rather than text to make sense of things.

That’s why we think it just makes sense to use visuals, as much as we can, when trying to help people understand advances in stem cell research. That’s precisely what our colleagues at U.C. San Diego are doing with a new show called “Stem Cell Science with Alysson Muotri”.

Alysson is a CIRM grantee who is doing some exciting work in developing a deeper understanding of autism. He’s also a really good communicator who can distill complex ideas down into easy to understand language.

The show features Alysson, plus other scientists at UCSD who are working hard to move the most promising research out of the lab and into clinical trials in people. Appropriately the first show in the series follows that path, exploring how discoveries made using tiny Zebrafish could hopefully lead to stem cell therapies targeting blood diseases like leukemia. This first show also highlights the important role that CIRM’s Alpha Stem Cell Clinic Network will play in bringing those therapies to patients.

You can find a sneak preview of the show on YouTube. The series proper will be broadcast on California local cable via the UCTV channel at 8:00 pm on Thursdays starting July 8, 2019. 

And if you really have a lot of time on your hands you can check out the more than 300 videos CIRM has produced on every aspect of stem cell research from cures for fatal diseases to questions to ask before taking part in a clinical trial.

How a see-through fish could one day lead to substitutes for bone marrow transplants

Human blood stem cells

For years researchers have struggled to create human blood stem cells in the lab. They have done it several times with animal models, but the human kind? Well, that’s proved a bit trickier. Now a CIRM-funded team at UC San Diego (UCSD) think they have cracked the code. And that would be great news for anyone who may ever need a bone marrow transplant.

Why are blood stem cells important? Well, they help create our red and white blood cells and platelets, critical elements in carrying oxygen to all our organs and fighting infections. They have also become one of the most important weapons we have to combat deadly diseases like leukemia and lymphoma. Unfortunately, today we depend on finding a perfect or near-perfect match to make bone marrow transplants as safe and effective as possible and without a perfect match many patients miss out. That’s why this news is so exciting.

Researchers at UCSD found that the process of creating new blood stem cells depends on the action of three molecules, not two as was previously thought.

Zebrafish

Here’s where it gets a bit complicated but stick with me. The team worked with zebrafish, which use the same method to create blood stem cells as people do but also have the advantage of being translucent, so you can watch what’s going on inside them as it happens.  They noticed that a molecule called Wnt9a touches down on a receptor called Fzd9b and brings along with it something called the epidermal growth factor receptor (EGFR). It’s the interaction of these three together that turns a stem cell into a blood cell.

In a news release, Stephanie Grainger, the first author of the study published in Nature Cell Biology, said this discovery could help lead to new ways to grow the cells in the lab.

“Previous attempts to develop blood stem cells in a laboratory dish have failed, and that may be in part because they didn’t take the interaction between EGFR and Wnt into account.”

If this new approach helps the team generate blood stem cells in the lab these could be used to create off-the-shelf blood stem cells, instead of bone marrow transplants, to treat people battling leukemia and/or lymphoma.

CIRM is also funding a number of other projects, several in clinical trials, that involve the use of blood stem cells. Those include treatments for: Beta Thalassemia; blood cancer; HIV/AIDS; and Severe Combined Immunodeficiency among others.

Mending Stem Cells: The Past, Present and Future of Regenerative Medicine

To Mend: (verb used with object) to make (something broken, worn, torn or otherwise damaged) whole, sound or usable by repairing.

It’s remarkable to believe, but today doctors literally have the tools to repair damaged cells. These tools are being used to treat people with diseases that were once incurable. The field of regenerative medicine has made tremendous progress in the last 15 years, but how did these tools come about and what is the experience of patients being treated with them?

These questions, and hopefully yours too, are going to be answered at the fourth annual CIRM Alpha Stem Cell Clinics Symposium on April 18, 2019 at the University of California at San Francisco.

UCSF Mission Bay Campus

The symposium is free, and the program is designed with patients and the public in mind, so don’t be shy and put your scientific thinking caps on! A complete agenda may be found here

Perhaps one of the most remarkable discoveries in the past decade are new tools that enable doctors to “edit” or correct a patient’s own DNA. DNA correction tools came about because of a remarkable string of scientific breakthroughs. The symposium will dive into this history and discuss  how these tools are being used today to treat patients.

One specific example of the promise that DNA editing holds is for those with sickle cell disease (SCD), a condition where patients’ blood forming stem cells contain a genetic error that causes the disease. The symposium will describe how the CIRM Alpha Stem Cell Clinics Network, a series of medical centers across California whose focus is on stem cell clinical trials, are supporting work aimed at mending blood cells to cure debilitating diseases like SCD.

Doctors, nurses and patients involved with these trials will be telling their stories and describing their experiences. One important focus will be how Alpha Clinic teams are partnering with community members to ensure that patients, interested in new treatments, are informed about the availability of clinical trials and receive sufficient information to make the best treatment choices.

The fourth annual CIRM Alpha Stem Cell Clinics Symposium is an opportunity for patients, their families and the public to meet the pioneers who are literally mending a patients own stem cells to cure their disease.

For registration information go here.


CIRM-funded clinical trial takes a combination approach to treating deadly blood cancers

Stained blood smear shows enlarged chronic lymphocytic leukemia cells among normal red blood cells. (UCSD Health)

A diagnosis of cancer often means a tough road ahead, with surgery, chemotherapy and radiation used to try and kill the tumor. Even then, sometimes cancer cells manage to survive and return later, spreading throughout the body. Now researchers at UC San Diego and Oncternal Therapeutics are teaming up with a combination approach they hope will destroy hard-to-kill blood cancers like leukemia.

The combination uses a monoclonal antibody called cirmtuzumab (so called because CIRM funding helped develop it) and a more traditional anti-cancer therapy called ibrutinib. Here’s how it is hoped this approach will work.

Ibrutinib is already approved by the US Food and Drug Administration (FDA) to treat blood cancers such as leukemia and lymphoma. But while it can help, it doesn’t always completely eradicate all the cancer cells. Some cancer stem cells are able to lie dormant during treatment and then start proliferating and spreading the cancer later. That’s why the team are pairing ibrutinib with cirmtuzumab.

In a news release announcing the start of the trial, UCSD’s Dr. Thomas Kipps,  said they hope this one-two punch combination will be more effective.

Thomas Kipps, UCSD

“As a result {of the failure to kill all the cancer cells}, patients typically need to take ibrutinib indefinitely, or until they develop intolerance or resistance to this drug. Cirmtuzumab targets leukemia and cancer stem cells, which are like the seeds of cancer. They are hard to find and difficult to destroy. By blocking signaling pathways that promote neoplastic-cell growth and survival, cirmtuzumab may have complementary activity with ibrutinib in killing leukemia cells, allowing patients potentially to achieve complete remissions that permit patients to stop therapy altogether.”

Because this is an early stage clinical trial, the goal is to first make sure the approach is safe, and second to identify the best dose and treatment schedule for patients.

The researchers hope to recruit 117 patients around the US. Some will get the cirmtuzumab and ibrutinib combination, some will get ibrutinib alone to see if one approach is more effective than the other.

CIRM has a triple investment in this research. Not only did our funding help develop cirmtuzumab, but CIRM is also funding this clinical trial and one of the trial sites is at UCSD, one of the CIRM Alpha Stem Cell Clinics.

CIRM’s Dr. Ingrid Caras says this highlights our commitment to our mission of accelerating stem cell therapies to patients with unmet medical needs.

“Our partnership with UC San Diego and the Alpha Stem Cell Clinics has enabled this trial to more quickly engage potential patient-participants. Being among the first to try new therapies requires courage and CIRM is grateful to the patients who are volunteering to be part of this clinical trial.”


Related Links:

Scientists repair spinal cord injuries in monkeys using human stem cells

Human neuronal stem cells extend axons (green). (Image UCSD)

An exciting development for spinal cord injury research was published this week in the journal Nature Medicine. Scientists from the University of San Diego School of Medicine transplanted human neural progenitor cells (NPCs) into rhesus monkeys that had spinal cord injuries. These cells, which are capable of turning into other cells in the brain, survived and robustly developed into nerve cells that improved the monkeys’ use of their hands and arms.

The scientists grafted 20 million human NPCs derived from embryonic stem cells into two-week-old spinal cord lesions in the monkeys. These stem cells were delivered with growth factors to improve their survival and growth. The monkeys were also treated with immunosuppressive drugs to prevent their immune system from rejecting the human cells.

After nine months, they discovered that the NPCs had developed into nerve cells within the injury site that extended past the injury into healthy tissue. These nerve extensions are called axons, which allow nerves to transmit electrical signals and instructions to other brain cells. During spinal cord injury, nerve cells and their axon extensions are damaged. Scientists have found it difficult to regenerate these damaged cells because of the inhibitory growth environment created at the injury site. You can compare it to the build-up of scar tissue after a heart attack. The heart has difficulty regenerating healthy heart muscle, which is instead replaced by fibrous scar tissue.

Excitingly, the UCSD team was able to overcome this hurdle in their current study. When they transplanted human NPCs with growth factors into the monkeys, they found that the cells were not affected by the inhibitory environment of the injury and were able to robustly develop into nerve cells and send out axon extensions.

Large numbers of human axons (green) emerge from a lesion/graft sites. Many axons travel along the interface (indicated by arrows) between spinal cord white matter (nerve fibers covered with myelin) and spinal cord gray matter (nerves without the whitish myelin sheathing). Image courtesy of Mark Tuszynski, UC San Diego School of Medicine.

The senior scientist on the study, Dr. Mark Tuszynski, explained how their findings in a large animal model are a huge step forward for the field in a UCSD Health news release:

“While there was real progress in research using small animal models, there were also enormous uncertainties that we felt could only be addressed by progressing to models more like humans before we conduct trials with people. We discovered that the grafting methods used with rodents didn’t work in larger, non-human primates. There were critical issues of scale, immunosuppression, timing and other features of methodology that had to be altered or invented. Had we attempted human transplantation without prior large animal testing, there would have been substantial risk of clinical trial failure, not because neural stem cells failed to reach their biological potential but because of things we did not know in terms of grafting and supporting the grafted cells.”

Dr. Tuszynski is a CIRM-grantee whose earlier research involved optimizing stem cell treatments for rodent models of spinal cord injury. We’ve blogged about that research previously on the Stem Cellar here and here.

Tuszynski recently was awarded a CIRM discovery stage research grant to develop a candidate human neural stem cell line that is optimized to repair the injured spinal cord and can be used in human clinical trials. He expressed cautious optimism about the future of this treatment for spinal cord injury patients emphasizing the need for patience and more research before arriving at clinical trials:

“We seem to have overcome some major barriers, including the inhibitory nature of adult myelin against axon growth. Our work has taught us that stem cells will take a long time to mature after transplantation to an injury site, and that patience will be required when moving to humans. Still, the growth we observe from these cells is remarkable — and unlike anything I thought possible even ten years ago. There is clearly significant potential here that we hope will benefit humans with spinal cord injury.”


Related Links:

Harnessing the body’s immune system to tackle cancer

Often on the Stem Cellar we write about work that is in a clinical trial. But getting research to that stage takes years and years of dedicated work. Over the next few months, we are profiling some of the scientists we fund who are doing Discovery (early stage) and Translational (pre-clinical) research, to highlight the importance of this work in developing the treatments that could ultimately save lives. 

This second profile in the series is by Ross Okamura, Ph.D., a science officer in CIRM’s Discovery & Translation Program.

Your immune system is your body’s main protection against disease; harnessing this powerful defense system to target a given disorder is known as immunotherapy.  There are different types of immunotherapies that have been developed over the years. These include vaccines to help generate antibodies against viruses, drugs to direct immune cell function and most recently, the engineering of immune cells to fight cancer.

Understanding How Immunotherapies Work

One of the more recent immunotherapy approaches to fight cancer that has seen rapid development is equipping a subset of immune cells (T cells) with a chimeric antigen receptor (CAR). In brief, CAR T ceIls are first removed from the patient and then engineered to recognize a specific feature of the targeted cancer cells.  This direct targeting of T cells to the cancer allows for an effective anti-cancer therapy made from your own immune system.

Simplified explanation of how CAR T cell therapies fight cancer. (Memorial Sloan Kettering)

For the first time this fall, two therapeutics employing CAR T cells targeting different types of blood cancers were approved for use by the US Food and Drug Administration (FDA) based on remarkable results found during the clinical trials. Specifically, Kymriah (developed by Novartis) was approved for treatment of acute lymphoblastic leukemia and Yescarta (developed by Kite Pharma) was approved for treatment of non-Hodgkin lymphoma.

There are drawbacks to the CAR T approach, however. Revving up the immune system to attack tumors can cause dangerous side effects. When CAR T cells enter the body, they trigger the release of proteins called cytokines, which join in the attack on the tumors. But this can also create what’s referred to as a cytokine storm or cytokine release syndrome (CRS), which can lead to a range of responses, from a mild fever to multi-organ failure and death. Balancing treatments to resolve CRS after it’s detected while still maintaining the treatment’s cancer-killing abilities is a significant challenge that remains to be overcome.  A second issue is that cancer cells can evade the immune system by no longer producing the target that the CAR-T therapy was designed to recognize. When this happens, the patient subsequently experiences a cancer relapse that is no longer treatable by the same cell therapy.

Natural Killer (NK) T cells represent another type of anti-cancer immunotherapy that is also being tested in clinical trials. NK cells are part of the innate immune system responsible for defending your body against both infection and tumor formation.  NK cells target stressed cells by releasing cell-penetrating proteins that poke holes in the cells leading to induced cell death.  As an immunotherapy, NK cells have the potential to avoid both the issues of CRS and cancer cell immune evasion as they release a more limited array of cytokines and do not rely on a specific single target to recognize tumors.  NK cells instead selectively target tumor cells due to the presence of stress-induced proteins on the cancer cells. In addition, the cancer cells lack other proteins that would normally send out a “I’m a healthy cell you can ignore me” message to NK cells. Without that message, NK cells target and kill those cancer cells.

Developing new immunotherapies against cancer

Dan Kaufman, UCSD

Dr. Dan Kaufman of the University of California at San Diego is a physician-scientist whose research group developed a method to produce functional NK cells from human pluripotent stem cells (PSC).  In order to overcome a major hurdle in the use of NK cells as an anti-cancer therapeutic, Dr. Kaufman is exploring using stem cells as a limitless source to produce a scalable, standardized, off-the-shelf product that could treat thousands of patients.  CIRM is currently funding Dr. Kaufman’s work under both a Discovery Quest award and a just recently funded Translational research award in order to try to advance this candidate approach.

In the CIRM Translational award, Dr. Kaufman is looking to cure acute myelogenous leukemia (AML) which in the US has a 5-year survival rate of 27% (National Cancer Institute, 2017) and is estimated to kill over 10,000 individuals this year (American Cancer Society, 2017).  He has previously shown that his stem cell-derived NK cells can kill human cancer cells in a dish and in mouse models, and his goals are to perform preliminary safety studies and to develop a process to scale his production of NK cells to support a clinical trial in people.  Since NK cells don’t require the patient and the donor to be a genetic match to be effective, a bank of PSC-derived NK cells derived from a single donor could potentially treat thousands of patients.

Looking forward, CIRM is also providing Discovery funding to Dr. Kaufman to explore ways to improve his existing approach against leukemia as well as expand the potential of his stem cell-derived NK cell therapeutic by engineering his cells to directly target solid tumors like ovarian cancer.

The field of pluripotent stem cell-based immunotherapies is full of game-changing potential and important innovations like Dr. Kaufman’s are still in the early stages.  CIRM recognizes the importance of supporting early stage research and is currently investing $27.9 million to fund 8 active Discovery and Translation awards in the cancer immunotherapy area.