Creating a diverse group of future scientists

Students in CIRM’s Bridges program showing posters of their work

If you have read the headlines lately, you’ll know that the COVID-19 pandemic is having a huge impact on the shipping industry. Container vessels are forced to sit out at anchor for a week or more because there just aren’t enough dock workers to unload the boats. It’s a simple rule of economics, you can have all the demand you want but if you don’t have the people to help deliver on the supply side, you are in trouble.

The same is true in regenerative medicine. The field is expanding rapidly and that’s creating a rising demand for skilled workers to help keep up. That doesn’t just mean scientists, but also technicians and other skilled individuals who can ensure that our ability to manufacture and deliver these new therapies is not slowed down.

That’s one of the reasons why CIRM has been a big supporter of training programs ever since we were created by the voters of California when they approved Proposition 71. And now we are kick-starting those programs again to ensure the field has all the talented workers it needs.

Last week the CIRM Board approved 18 programs, investing more than $86 million, as part of the Agency’s Research Training Grants program. The goal of the program is to create a diverse group of scientists with the knowledge and skill to lead effective stem cell research programs.

The awards provide up to $5 million per institution, for a maximum of 20 institutions, over five years, to support the training of predoctoral graduate students, postdoctoral trainees, and/or clinical trainees.

This is a revival of an earlier Research Training program that ran from 2006-2016 and trained 940 “CIRM Scholars” including:

• 321 PhD students
• 453 Postdocs
• 166 MDs

These grants went to academic institutions from UC Davis in Sacramento to UC San Diego down south and everywhere in-between. A 2013 survey of the students found that most went on to careers in the industry.

  • 56% continued to further training
  • 14% advanced to an academic research faculty position
  • 10.5% advanced to a biotech/industry position
  • 12% advanced to a non-research position such as teaching, medical practice, or foundation/government work

The Research Training Grants go to:

AWARDINSTITUTIONTITLEAMOUNT
EDUC4-12751Cedars-SinaiCIRM Training Program in Translational Regenerative Medicine    $4,999,333
EDUC4-12752UC RiversideTRANSCEND – Training Program to Advance Interdisciplinary Stem Cell Research, Education, and Workforce Diversity    $4,993,115
EDUC4-12753UC Los AngelesUCLA Training Program in Stem Cell Biology    $5 million
EDUC4-12756University of Southern CaliforniaTraining Program Bridging Stem Cell Research with Clinical Applications in Regenerative Medicine    $5 million
EDUC4-12759UC Santa CruzCIRM Training Program in Systems Biology of Stem Cells    $4,913,271
EDUC4-12766Gladstone Inst.CIRM Regenerative Medicine Research Training Program    $5 million
EDUC4-12772City of HopeResearch Training Program in Stem Cell Biology and Regenerative Medicine    $4,860,989
EDUC4-12782StanfordCIRM Scholar Training Program    $4,974,073
EDUC4-12790UC BerkeleyTraining the Next Generation of Biologists and Engineers for Regenerative Medicine    $4,954,238
EDUC4-12792UC DavisCIRM Cell and Gene Therapy Training Program 2.0    $4,966,300
EDUC4-12802Children’s Hospital of Los AngelesCIRM Training Program for Stem Cell and Regenerative Medicine Research    $4,999,500
EDUC4-12804UC San DiegoInterdisciplinary Stem Cell Training Grant at UCSD III    $4,992,446
EDUC4-12811ScrippsTraining Scholars in Regenerative Medicine and Stem Cell Research    $4,931,353
EDUC4-12812UC San FranciscoScholars Research Training Program in Regenerative Medicine, Gene Therapy, and Stem Cell Research    $5 million
EDUC4-12813Sanford BurnhamA Multidisciplinary Stem Cell Training Program at Sanford Burnham Prebys Institute, A Critical Component of the La Jolla Mesa Educational Network    $4,915,671  
EDUC4-12821UC Santa BarbaraCIRM Training Program in Stem Cell Biology and Engineering    $1,924,497
EDUC4-12822UC IrvineCIRM Scholars Comprehensive Research Training Program  $5 million
EDUC4-12837Lundquist Institute for Biomedical InnovationStem Cell Training Program at the Lundquist Institute    $4,999,999

These are not the only awards we make to support training the next generation of scientists. We also have our SPARK and Bridges to Stem Cell Research programs. The SPARK awards are for high school students, and the Bridges program for graduate or Master’s level students.

Tiny tools for the smallest of tasks, editing genes

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Developing new tools to edit genes

Having the right tools to do a job is important. Try using a large screwdriver to tighten the screws on your glasses and you quickly appreciate that it’s not just the type of tool that’s important, it’s also the size. The same theory applies to gene editing. And now researchers at Stanford have developed a tool that can take on even the tiniest of jobs.

The tool involves the use of CRISPR. You may well have heard about CRISPR. The magazine New Scientist described it this way: “CRISPR is a technology that can be used to edit genes and, as such, will likely change the world.” For example, CIRM is funding research using CRISPR to help children born with severe combined immunodeficiency, a rare, fatal immune disorder.  

There’s just one problem. Right now, CRISPR is usually twinned with a protein called Cas9. Together they are used to remove unwanted genes and insert a corrected copy of the bad gene. However, that CRISPR-Cas9 combination is often too big to fit into all our cells. That may seem hard to understand for folks like me with a limited science background, but trust the scientists, they aren’t making this stuff up.

To address that problem, Dr. Stanley Qi and his team at Stanford created an even smaller version, one they call CasMINI, to enable them to go where Cas9 can’t go. In an article on Fierce Biotech, Dr. Qi said this mini version has some big benefits: “If people sometimes think of Cas9 as molecular scissors, here we created a Swiss knife containing multiple functions. It is not a big one, but a miniature one that is highly portable for easy use.”

How much smaller is the miniature version compared to the standard Cas9? About half the size, 529 amino acids, compared to Cas9’s 1,368 amino acids.”

The team conclude their study in the journal Molecular Cell saying this could have widespread implications for the field: “This provides a new method to engineer compact and efficient CRISPR-Cas effectors that can be useful for broad genome engineering applications, including gene regulation, gene editing, base editing, epigenome editing, and chromatin imaging.”

National Academy of Medicine honors CIRM Grantees

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As someone who is not always as diligent as he would like to be about sending birthday cards on time, I’m used to sending belated greetings to people. So, I have no shame in sending belated greetings to four CIRM grantees who were inducted into the National Academy of Medicine in 2020.

I say four, but it’s really three and a half. I’ll explain that later.

Being elected to the National Academy of Medicine is, in the NAM’s own modest opinion, “considered one of the highest honors in the fields of health and medicine and recognizes individuals who have demonstrated outstanding professional achievement and commitment to service.”

To be fair, NAM is right. The people elected are among the best and brightest in their field and membership is by election from the other members of NAM, so they are not going to allow any old schmuck into the Academy (which could explain why I am still waiting for my membership).

The CIRM grantees elected last year are:

Dr. Antoni Ribas: Photo courtesy UCLA

Antoni Ribas, MD, PhD, professor of medicine, surgery, and molecular and medical pharmacology, U. C. Los Angeles.

Dr. Ribas is a pioneer in cancer immunology and has devoted his career to developing new treatments for malignant melanoma. When Dr. Ribas first started malignant melanoma was an almost always fatal skin cancer. Today it is one that can be cured.

In a news release Dr. Ribas said it was a privilege to be honored by the Academy: “It speaks to the impact immunotherapy has played in cancer research. When I started treating cases of melanoma that had metastasized to other organs, maybe 1 in 20 responded to treatment. Nobody in their right mind wanted to be a specialist in this field. It was the worst of the worst cancers.”

Looks like he chose his career path wisely.

Dr. Jeffrey Goldberg: Photo courtesy Stanford

Jeffrey Louis Goldberg, MD, PhD, professor and chair of ophthalmology, Stanford University, Palo Alto, Calif.

Dr. Goldberg was honored for his contribution to the understanding of vision loss and ways to reverse it. His lab has developed artificial retinas that transmit images down the optic nerve to the brain through tiny silicon chips implanted in the eye. He has also helped use imaging technology to better improve our ability to detect damage in photoreceptor cells (these are cells in the retina that are responsible for converting light into signals that are sent to the brain and that give us our color vision and night vision)

In a news release he expressed his gratitude saying: “I look forward to serving the goals of the National Academies, and to continuing my collaborative research efforts with my colleagues at the Byers Eye Institute at Stanford and around the world as we further our efforts to combat needless blindness.”

Dr. Mark Anderson; photo courtesy UCSF

Mark S. Anderson, MD, PhD, professor in Diabetes Research, Diabetes Center, U. C. San Francisco.

Dr. Anderson was honored for being a leader in the study of autoimmune diseases such as type 1 diabetes. This focus extends into the lab, where his research examines the genetic control of autoimmune diseases to better understand the mechanisms by which immune tolerance is broken.

Understanding what is happening with the immune system, figuring out why it essentially turns on the body, could one day lead to treatments that can stop that, or even reverse it by boosting immune activity.

Dr. John Dick: Photo courtesy University Health Network, Toronto

Remember at the beginning I said that three and a half CIRM grantees were elected to the Academy, well, Canadian researcher, Dr. John Dick is the half. Why? Well, because the award we funded actually went to UC San Diego’s Dennis Carson but it was part of a Collaborative Funding Partnership Program with Dr. Dick at the University of Toronto. So, we are going to claim him as one of our own.

And he’s a pretty impressive individual to partner with. Dr. Dick is best known for developing a test that led to the discovery of leukemia stem cells. These are cells that can evade surgery, chemotherapy and radiation and which can lead to patients relapsing after treatment. His work helped shape our understanding of cancer and revealed a new strategy for curing it.

CIRM funds clinical trials targeting heart disease, stroke and childhood brain tumors

Gary Steinberg (Jonathan Sprague)

Heart disease and stroke are two of the leading causes of death and disability and for people who have experienced either their treatment options are very limited. Current therapies focus on dealing with the immediate impact of the attack, but there is nothing to deal with the longer-term impact. The CIRM Board hopes to change that by funding promising work for both conditions.

Dr. Gary Steinberg and his team at Stanford were awarded almost $12 million to conduct a clinical trial to test a therapy for motor disabilities caused by chronic ischemic stroke.  While “clot busting” therapies can treat strokes in their acute phase, immediately after they occur, these treatments can only be given within a few hours of the initial injury.  There are no approved therapies to treat chronic stroke, the disabilities that remain in the months and years after the initial brain attack.

Dr. Steinberg will use embryonic stem cells that have been turned into neural stem cells (NSCs), a kind of stem cell that can form different cell types found in the brain.  In a surgical procedure, the team will inject the NSCs directly into the brains of chronic stroke patients.  While the ultimate goal of the therapy is to restore loss of movement in patients, this is just the first step in clinical trials for the therapy.  This first-in-human trial will evaluate the therapy for safety and feasibility and look for signs that it is helping patients.

Another Stanford researcher, Dr. Crystal Mackall, was also awarded almost $12 million to conduct a clinical trial to test a treatment for children and young adults with glioma, a devastating, aggressive brain tumor that occurs primarily in children and young adults and originates in the brain.  Such tumors are uniformly fatal and are the leading cause of childhood brain tumor-related death. Radiation therapy is a current treatment option, but it only extends survival by a few months.

Dr. Crystal Mackall and her team will modify a patient’s own T cells, an immune system cell that can destroy foreign or abnormal cells.  The T cells will be modified with a protein called chimeric antigen receptor (CAR), which will give the newly created CAR-T cells the ability to identify and destroy the brain tumor cells.  The CAR-T cells will be re-introduced back into patients and the therapy will be evaluated for safety and efficacy.

Joseph Wu Stanford

Stanford made it three in a row with the award of almost $7 million to Dr. Joe Wu to test a therapy for left-sided heart failure resulting from a heart attack.  The major issue with this disease is that after a large number of heart muscle cells are killed or damaged by a heart attack, the adult heart has little ability to repair or replace these cells.  Thus, rather than being able to replenish its supply of muscle cells, the heart forms a scar that can ultimately cause it to fail.  

Dr. Wu will use human embryonic stem cells (hESCs) to generate cardiomyocytes (CM), a type of cell that makes up the heart muscle.  The newly created hESC-CMs will then be administered to patients at the site of the heart muscle damage in a first-in-human trial.  This initial trial will evaluate the safety and feasibility of the therapy, and the effect upon heart function will also be examined.  The ultimate aim of this approach is to improve heart function for patients suffering from heart failure.

“We are pleased to add these clinical trials to CIRM’s portfolio,” says Maria T. Millan, M.D., President and CEO of CIRM.  “Because of the reauthorization of CIRM under Proposition 14, we have now directly funded 75 clinical trials.  The three grants approved bring forward regenerative medicine clinical trials for brain tumors, stroke, and heart failure, debilitating and fatal conditions where there are currently no definitive therapies or cures.”

Hitting our Goals: Accelerating to the finish line

Way, way back in 2015 – seems like a lifetime ago doesn’t it – the team at CIRM sat down and planned out our Big 6 goals for the next five years. The end result was a Strategic Plan that was bold, ambitious and set us on course to do great things or kill ourselves trying. Well, looking back we can take some pride in saying we did a really fine job, hitting almost every goal and exceeding them in some cases. So, as we plan our next five-year Strategic Plan we thought it worthwhile to look back at where we started and what we achieved. Goal #6 was Accelerate.

Ever wonder how long it takes for a drug or therapy to go from basic research to approval by the US Food and Drug Administration (FDA)? Around 12 years on average is the answer. That’s a long time. And it can take even longer for stem cell therapies to go that same distance.

There are a lot of reasons why it takes so long (safety being a hugely important element) but when we were sitting down in 2015 to put together our Strategic Plan we wanted to find a way to speed up that process, to go faster, without in any way reducing the focus on safety.

So, we set a goal of reducing the time it takes from identifying a stem cell therapy candidate to getting an Investigational New Drug (IND) approval from the FDA, which means it can be tested in a clinical trial. At the time it was taking us around eight years, so we decided to go big and try to reduce that time in half, to four years.

Then the question was how were we going to do that? Well, before we set the goal we did a tour of the major biomedical research institutions in California – you know, University of California Los Angeles (UCLA) UC San Francisco, Stanford etc. – and asked the researchers what would help them most. Almost without exception said “a clearing house”, a way to pair early stage investigators with later stage partners who possess the appropriate expertise and interest to advance the project to the next stage of development, e.g., helping a successful basic science investigator find a qualified partner for the project’s translational research phase.

So we set out to do that. But we didn’t stop there. We also created what we called Clinical Advisory Panels or CAPs. These consisted of a CIRM Science Officer with expertise on a particular area of research, an expert on the kind of research being done, and a Patient Representative. The idea was that CAPs would help guide and advise the research team, helping them overcome specific obstacles and get ready for a clinical trial. The Patient Representative could help the researchers understand what the needs of the patient community was, so that a trial could take those into account and be more likely to succeed. For us it wasn’t enough just to fund promising research, we were determined to do all we could to support the team behind the project to advance their work.

How did we do. Pretty good I would have to say. For our Translational stage projects, the average amount of time it took for them to move to the CLIN1 stage, the last stage before a clinical trial, was 4.18 years. For our CLIN1 programs, 73 percent of those achieved their IND within 2 years, meaning they were then ready to actually start an FDA-sanctioned clinical trial.

Of course moving fast doesn’t guarantee that the therapy will ultimately prove effective. But for an agency whose mission is “to accelerate stem cell therapies to patients with unmet medical needs”, going slow is not an option.

CIRM Bridges program prepared student for research of a rare disease

Ian Blong, Ph.D., CIRM San Francisco State University Bridges to Stem Cell Research Alumnus

Recently, The New York Times released a powerful article that tells the stories of four different families navigating the challenges of having a family member with a rare disease. One of these stories focused on Matt Wilsey, a tech entrepreneur and investor in California’s Silicon Valley, and his daughter Grace, who was born with an extremely rare genetic disorder named NGLY1 deficiency. This genetic disorder causes developmental delay, intellectual disability, seizures, and other movement issues.

Matt and Kristen Wilsey with their 10-year-old daughter Grace, who has a rare genetic disorder, at the Grace Science headquarters in Menlo Park, Calif.
Image Credit: James Tensuan for The New York Times

Matt decided to put his entrepreneurial and networking skills to good use in order to form Grace Science Foundation, an organization whose focus is to pioneer approaches to scientific discovery in order to develop a cure for NGLY1 deficiency. One researcher that Matt brought on board was Carolyn Bertozzi, Ph.D., a chemist from Stanford University. A graduate student in her laboratory, Ian Blong, Ph.D., decided to study NGLY1 and was able to complete his dissertation while working on this topic at Stanford University.

Ian’s journey towards obtaining his Ph.D. started after being accepted into the San Francisco State University (SFSU) CIRM Bridges to Stem Cell Research Master’s Program. CIRM funding for this program allowed students like Ian to take courses at SFSU while also working in labs at world renown institutions in the Bay Area such as UCSF, Stanford, and UC Berkeley.

Carolyn Bertozzi, Ph.D.
Image Credit: L.A. Cicero

In exploring the various options afforded to him by the CIRM, Ian found Dr. Bertozzi’s lab at UC Berkeley, where he focused on early stage discovery research. His master’s thesis project focused on how to generate rare neuronal and and neural crest cells from human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs). Both of these stem cell types can generate virtually any kind of cell, but iPSCs are unique in that they can be generated from the adult cells (such as skin) of a patient.

Ian decided to continue his studies in Dr. Bertozzi’s lab by continuing his research in a Ph.D. program at UC Berkeley. He credits the SFSU CIRM Bridges Program with giving him the opportunity to work under a prestigious PI and in her lab at UC Berkeley, which allowed him to continue his studies there.

“The CIRM Bridges Program gave me the confidence and resources to pursue my dreams. Being able to have the capability of going to Berkeley and do research with top tier scientists along with the support from CIRM. Without CIRM, I wouldn’t have had the courage to go to those universities to get my foot in the door.”

Eventually, Dr. Bertozzi move her operations to Stanford University and Ian continued his Ph.D. studies there. Stanford provided him the opportunity to focus more on the translational stage, which is an area of research aimed at developing a therapeutic candidate. Going into his Ph.D. work, Ian was able to build upon his previous “discovery stage” knowledge of generating neuronal and neural crest cells from iPSCS and hESCs.

An area of his work at Stanford focused on generating neural crest cells from iPSCs of those with NGLY1 deficiency. The goal was to identify a phenotype, which is an observable characteristic such as physical form. Identifying this would help better understand potential differentiation pathways that underlie NGLY1 deficiency, which could lead to the development a potential treatment for the condition.

Flash forward to present day and Ian is still using the knowledge he learned from his time in the SFSU CIRM Bridges to Stem Cell Research Program. He is currently a scientist at the healthcare company Roche, where his focus is on manufacturing future diagnostics and therapeutics on a much larger scale, a complex and extremely critical process necessary in widely distributing potential stem cell-based treatments.

Ian’s experience and opportunities provided to him is just one of the many examples of how the various CIRM Bridges Programs across California have given students the resources needed to become the next generation of scientists.

Explaining COVID can be a pitch

When people ask me what I do at CIRM I sometimes half-jokingly tell them that I’m the official translator: I take complex science and turn it into everyday English. That’s important. The taxpayers of California have a right to know how their money is being spent and how it might benefit them. But that message can be even more effective when it comes from the scientists themselves.

Recently we asked some of the scientists we are funding to do research into COVID-19 to record what’s called an “elevator pitch”. This is where they prepare an explanation of their work that is in ordinary English and is quite short, short enough to say it to someone as you ride in an elevator. Hence the name.

It sounds easy enough. But it’s not. When you are used to talking in the language of science day in and day out, suddenly switching codes to talk about your work in plain English can take some practice. Also, you have spent years, often decades, on this work and to have to explain it in around one minute is no easy thing.

But our researchers rose to the challenge. Here’s some examples of just how well they did.

Building a progressive pipeline

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)

Dashed Dreams and New Hope: A Quest to Cure Thymic Deficiency

By Kelly Shepard, PhD., CIRM’s Associate Director, Discovery & Translation

CIRM has previously blogged about advances in treating certain forms of  “bubble baby” disease”, where a person is born with a defect in their blood forming stem cells that results in a deficient immune system, rendering them vulnerable to lethal infections by all manner of bacteria, virus or germ.

If a suitable donor can be found, or if the patient’s own defective cells can be corrected through gene therapy approaches, it is now possible to treat or cure such disorders through a bone marrow transplant. In this procedure, healthy blood stem cells are infused into the patient, taking up residence in his or her bone marrow and dividing to give rise to functioning immune cells such as T cells and B cells.

Unfortunately, there is another type of “bubble baby” disease that cannot be treated by providing healthy blood stem cells, because the defective immune system is caused by a different culprit altogether- a missing or dysfunctional thymus.

Created for the National Cancer Institute, http://www.cancer.gov

T Cells Go to School

What is a thymus?  Most of us give little thought to this leaf-shaped organ, which is large and important in our early childhoods, but becomes small and inconspicuous as we age. This transformation belies the critical role a thymus plays in the development of our adaptive immune systems, which takes place in our youth: to prepare our bodies to fight infections for the rest of our lives.

One might think of the thymus as a “school”, where immature T cells go to “learn” how to recognize and attack foreign antigens (surface markers), such as those found on microorganisms or tissues from other individuals. The thymus also “teaches” our immune system to distinguish “self” from “other” by eliminating any T cells that attack our own tissues. Without this critical function, our immune system could inadvertently turn against us, causing serious autoimmune disorders such as ulcerative colitis and myasthenia gravis.

Many children with a severely deficient or absent thymus, referred to as athymia, have inherited a chromosome that is missing a key stretch of genes on a region called 22q11. Doctors believe perhaps 1/2000-1/4000 babies are born with some type of deletion in this region, which leads to a variable spectrum of disorders called 22q11 syndrome that can affect just about any part of the body, and can even cause learning disabilities and mental illness.

Individuals with one form of 22q11, called DiGeorge Syndrome, are particularly affected in the heart, thymus, and parathyroid glands. In the United States, about 20 infants are born per year with the “complete” and most severe form of DiGeorge Syndrome, who lack a thymus altogether, and have severely depressed numbers of T cells for fighting infections. Without medical intervention, this condition is usually fatal by 24 months of age.

Optimism and Setback                                                                  

Although there are no therapies approved by the Food and Drug Administration (FDA) for pediatric athymia, Dr. Mary Louise Markert at Duke University and Enzyvant, Inc. have been pioneering an experimental approach to treat children with complete DiGeorge syndrome.

In this procedure, discarded thymic tissues are collected from infants undergoing cardiac surgery, where some of the thymus needs to be removed in order for the surgeon to gain access to the heart. These tissues are processed to remove potentially harmful donor T cells and then transplanted into the thigh of an athymic DiGeorge patient.

Results from early clinical trials seemed promising, with more than 70% of patients surviving, including several who are now ten years post-transplant. Based on those results, in June of 2019 Enzyvant applied to the FDA for a Biologics License Application (BLA), which is needed to be able to sell the therapy in the US. Unfortunately, only a few months later, Enzyvant announced that the FDA had declined to approve the BLA due to manufacturing concerns.

While it may be possible to address these issues in time, the need to step back to the drawing board was a devastating blow to the DiGeorge Community, who have waited decades for a promising treatment to emerge on the horizon.

New Opportunities

Despite the setback, there is reason to hope. In early 2019, CIRM granted a “Quest” Award to team of investigators at Stanford University to develop a novel stem cell based approach for treating thymic deficiency. Co-led by Katja Weinacht, a pediatric hematologist/oncologist, and Vittorio Sebastiano, a stem cell expert and developmental biologist, the team’s strategy is to coax induced pluripotent stem cells (iPS) in the laboratory to differentiate into thymic tissue, which could then be transplanted into patients using the route pioneered by Duke and Enzyvant.

Katja Weinacht: Photo courtesy Stanford Children’s Health

The beauty of this new approach is that pluripotent stem cells are essentially immortal in culture, providing an inexhaustible supply of fresh thymic cells for transplant, thereby allowing greater control over the quality and consistency of donor tissues. A second major advantage is the possibility of using pluripotent cells from the patient him/herself as the source, which should be perfectly immune-matched and alleviate the risk of rejection and autoimmunity that comes with use of donated tissues.

Vittorio Sebastiano: Photo courtesy Stanford

Sounds easy, so what are the challenges? As with many regenerative medicine approaches, the key is getting a pluripotent stem cell to differentiate into the right type of cells in the lab, which is a very different environment than what cells experience naturally when they develop in the context of an embryo and womb, where many cells are interacting and providing complex, instructive cues to one another. The precise factors and timing all need to be worked out and in most cases, this is done with an incomplete knowledge of human development.

A second challenge relates to using cells from DiGeorge patients to produce thymic tissue, which are missing several genes on their 22nd chromosome and will likely require sophisticated genetic engineering to restore this ability.

Fortunately, Drs. Weinacht and Sebastiano are up to the challenge, and have already made progress in differentiating human induced pluripotent stem cells (iPS) into thymic lineage intermediates that appear to be expressing the right proteins at the right time. They plan to combine these cells with engineered materials to create a three-dimensional (3D) tissue that more closely resembles an authentic organ, and which can be tested for functionality in athymic mice.

There is more work to be done, but these advances, along with continued technological improvements and renewed efforts from Enzyvant, could forge a path to the clinic and  lead to a brighter future for patients suffering from congenital athymia and other forms of thymic dysfunction.

 

Stem cell progress and promise in fighting leukemia

Computer illustration of a cancerous white blood cell in leukemia.

There is nothing you can do to prevent or reduce your risk of leukemia. That’s not a very reassuring statement considering that this year alone almost 62,000 Americans will be diagnosed with leukemia; almost 23,000 will die from the disease. That’s why CIRM is funding four clinical trials targeting leukemia, hoping to develop new approaches to treat, and even cure it.

That’s also why our next special Facebook Live “Ask the Stem Cell Team” event is focused on this issue. Join us on Thursday, August 29th from 1pm to 2pm PDT to hear a discussion about the progress in, and promise of, stem cell research for leukemia.

We have two great panelists joining us:

Dr. Crystal Mackall, has many titles including serving as the Founding Director of the Stanford Center for Cancer Cell Therapy.  She is using an innovative approach called a Chimeric Antigen Receptor (CAR) T Cell Therapy. This works by isolating a patient’s own T cells (a type of immune cell) and then genetically engineering them to recognize a protein on the surface of cancer cells, triggering their destruction. This is now being tested in a clinical trial funded by CIRM.

Natasha Fooman. To describe Natasha as a patient advocate would not do justice to her experience and expertise in fighting blood cancer and advocating on behalf of those battling the disease. For her work she has twice been named “Woman of the Year” by the Leukemia and Lymphoma Society. In 2011 she was diagnosed with a form of lymphoma that was affecting her brain. Over the years, she would battle lymphoma three times and undergo chemotherapy, radiation and eventually a bone marrow transplant. Today she is cancer free and is a key part of a CIRM team fighting blood cancer.

We hope you’ll join us to learn about the progress being made using stem cells to combat blood cancers, the challenges ahead but also the promising signs that we are advancing the field.

We also hope you’ll take an active role by posting questions on Facebook during the event, or sending us questions ahead of time to info@cirm.ca.gov. We will do our best to address as many as we can.

Here’s the link to the event, feel free to share this with anyone you think might be interested in joining us for Facebook Live “Ask the Stem Cell Team about Leukemia”