CIRM Board Approves Third Clinical Trial for COVID-19

Dr. Xiaokui Zhang (left), Dr. Albert Wong (center), and Dr. Preet Chaudhary (right)

Today the governing Board of the California Institute for Regenerative Medicine (CIRM) awarded $750,000 to Dr. Xiaokui Zhang at Celularity to conduct a clinical trial for the treatment of COVID-19.  This brings the total number of CIRM clinical trials to 64, including three targeting the coronavirus.

This trial will use blood stem cells obtained from the placenta to generate natural killer (NK) cells, a type of white blood cell that is a vital part of the immune system, and administer them to patients with COVID-19.  NK cells play an important role in defense against cancer and in fighting off viral infections.  The goal is to administer these cells to locate the active sites of COVID-19 infection and destroy the virus-infected cells.  These NK cells have been used in two other clinical trials for acute myeloid leukemia and multiple myeloma.

The Board also approved two additional awards for Discovery Stage Research (DISC2), which promote promising new technologies that could be translated to enable broad use and improve patient care.

One award for $100,000 was given to Dr. Albert Wong at Stanford.  Dr. Wong has recently received an award from CIRM to develop a vaccine that produces a CD8+ T cell response to boost the body’s immune response to remove COVID-19 infected cells.  The current award will enable him to expand on the initial approach to increase its potential to impact the Latinx and African American populations, two ethnicities that are disproportionately impacted by the virus in California.

The other award was for $249,996 and was given to Dr. Preet Chaudhary at the University of Southern California.  Dr. Chaudary will use induced pluripotent stem cells (iPSCs) to generate natural killer cells (NK). These NK cells will express a chimeric antigen receptor (CAR), a synthetic receptor that will directly target the immune cells to kill cells infected with the virus.  The ultimate goal is for these iPSC-NK-CAR cells to be used as a treatment for COVID-19. 

“These programs address the role of the body’s immune T and NK cells in combatting viral infection and CIRM is fortunate enough to be able to assist these investigators in applying experience and knowledge gained elsewhere to find targeted treatments for COVID-19” says Dr. Maria T. Millan, the President & CEO of CIRM. “This type of critical thinking reflects the resourcefulness of researchers when evaluating their scientific tool kits.  Projects like these align with CIRM’s track record of supporting research at different stages and for different diseases than the original target.”

The CIRM Board voted to endorse a new initiative to refund the agency and provide it with $5.5 billion to continue its work. The ‘California Stem Cell Research, Treatments and Cures Initiative of 2020 will appear on the November ballot. 

The Board also approved a resolution honoring Ken Burtis, PhD., for his long service on the Board. Dr. Burtis was honored for his almost four decades of service at UC Davis as a student, professor and administrator and for his 11 years on the CIRM Board as both a member and alternate member. In the resolution marking his retirement the Board praised him, saying “his experience, commitment, knowledge, and leadership, contributed greatly to the momentum of discovery and the future therapies which will be the ultimate outcome of the dedicated work of the researchers receiving CIRM funding.”

Jonathan Thomas, the Chair of the Board, said “Ken has been invaluable and I’ve always found him to have tremendous insight. He has served as a great source of advice and inspiration to me and to the ICOC in dealing with all the topics we have had to face.” 

Lauren Miller Rogen thanked Dr. Burtis, saying “I sat next to you at my first meeting and was feeling so extraordinarily overwhelmed and you went out of your way to explain all these big science words to me. You were always a source of help and support, and you explained things to me in a way that I always appreciated with my normal brain.”

Dr. Burtis said it has been a real honor and privilege to be on the Board. “I’ve been amazed and astounded at the passion and dedication that the Board and CIRM staff have brought to this work. Every meeting over the years there has been a moment of drama and then resolution and this Board always manages to reach agreement and serve the people of California.”

Stem Cell Agency Board Approves Three More Projects Targeting COVID-19

Dr. Jianhua Yu (left), Dr. Helen Blau (center), and Dr. Albert Wong (right)

The COVID-19 virus targets many different parts of the body, often with deadly or life-threatening consequences. This past Friday the governing Board of the California Institute for Regenerative Medicine (CIRM) approved investments in three early-stage research programs taking different approaches to battling the virus.

Dr. Jianhua Yu at the Beckman Research Institute of City of Hope was awarded $150,000 to use stem cells from umbilical cord blood to attack the virus. Dr. Yu and his team have many years of experience in taking cord blood cells and turning them into what are called chimeric antigen receptor (CAR) natural killer (NK) cells. The goal is to deploy these CAR NK cells to specifically target cells infected with COVID-19. This leverages the body of work at the City of Hope to develop this technology for cancer.

Dr. Helen Blau of Stanford University was awarded $149,996 to target recovery of muscle stem cells of the diaphragm in COVID-19 patients who have an extended period on a ventilator.

Patients with severe coronavirus often suffer respiratory failure and end up on mechanical ventilation that takes over the work of breathing. Over time, the diaphragm, the main muscle responsible for inhaling and exhaling, weakens and atrophies. There is no treatment for this kind of localized muscle wasting and it is anticipated that some of these patients will take months, if not years, to fully recover. Dr. Blau’s team proposes to develop a therapy with Prostaglandin E2 and Bupivacaine based on data generated by Dr. Blau’s group that these drugs, already approved by the FDA for other indications, have the potential to stimulate muscle stem cell recovery.

Dr. Albert Wong, also from Stanford University, was awarded $149,999 to develop vaccine candidates against COVID-19.

Most vaccine candidates are focused on getting the body to produce an antibody response to block the virus. However, Dr. Wong thinks that to be truly effective, a vaccine also needs to produce a CD8+ T cell response to augment an effective immune response to remove the COVID-19 infected cells that are hijacked by the virus to spread and cause illness.  This team will use the experience it gained using CIRM funds to vaccine against glioblastoma, a deadly brain cancer, to advance a similar approach to produce an effective cellular immune response to combat COVID-19.  

“CIRM is committed to supporting novel, multi-pronged approaches to battle this COVID-19 crisis that leverage solid science and knowledge gained in other areas.” says Dr. Maria T. Millan, the President & CEO of CIRM. “These three projects highlight three very different approaches to combatting the acute devastating health manifestations of COVID-19 as well as the debilitating sequelae that impact the ability to recover from the acute illness. Through this COVID funding opportunity, CIRM is enabling researchers to re-direct work they have already done, often with CIRM support, to quickly develop new approaches to COVID-19.”

Study shows that exercise rejuvenates muscle stem cells of old mice

Dr. Thomas Rando, Stanford University
Image Credit: Steve Fisch/Stanford University Website

While we’re all at home and practicing social distancing during this global pandemic, it has become a challenge to get in daily exercise. Aside from outward physical appearance, what other benefits does exercise hold? Dr. Thomas Rando and his team at Stanford University explored this question in more detail in a CIRM supported animal study.

The Stanford research team found that exercise played a key role in restoring the youthful properties in the muscle stem cells of old mice. Muscle stem cells play an important role in tissue regeneration. They are usually on standby alongside muscle fibers in a resting state known as quiescence until called upon to repair damage.

For this study, the researchers wanted to see if voluntary exercise had an effect on the muscle stem cells in mice. Older mice that were 20 months old, the equivalent of 60-70 human years, were given an exercise wheel where they were allowed to run at will. Younger mice that were 3-4 months old, the equivalent of 20-30 human years, were also given an exercise wheel and allowed to run at will. A separate group of younger and older mice were given a wheel that didn’t rotate to compare them with the groups of mice that exercised.

They found that the older animals that had exercised regularly were significantly better at repairing muscle damage compared to their counterparts that did not exercise. However, this exercise benefit was not observed between the younger group of mice.

The researchers also transplanted the muscle stem cells from the older mice that had exercised into younger mice that had not exercised. They found that the muscle stem cells from the older mice contributed more to the repair process than did those from the non-exercising mice.

What was also surprising is that injecting blood from an old mouse that had exercised into an old mouse that hadn’t created a similar benefit in the muscle stem cells. This finding suggests that exercise simulates the production of some factors that then circulate in the blood and enhance the function of older stem cells.

Lastly, the researchers were ably to identify a molecular pathway that activates the resting muscle stem cells in response to damage.

In a press release, Dr. Rando discusses how this discovery could potentially lead to the development of a drug that could rejuvenate muscle stem cells.

“If we could develop a drug that mimics this effect, we may be able to experience the benefit without having to do months of exercise.”

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

Big time validation for early support

It’s not every day that a company and a concept that you helped support from the very beginning gets snapped up for $4.9 billion. But that’s what is happening with Forty Seven Inc. and their anti-cancer therapies. Gilead, another California company by the way, has announced it is buying Forty Seven Inc. for almost $5 billion.

The deal gives Gilead access to Forty Seven’s lead antibody therapy, magrolimab, which switches off CD47, a kind of “do not eat me” signal that cancer cells use to evade the immune system.

CIRM has supported this program from its very earliest stages, back in 2013, when it was a promising idea in need of funding. Last year we blogged about the progress it has made from a hopeful concept to an exciting therapy.

When Forty Seven Inc. went public in 2018, Dr. Irv Weissman, one of the founders of the company, attributed a lot of their success to CIRM’s support.

Dr. Irv Weissman

“The story of the funding of this work all of the way to its commercialization and the clinical trials reported in the New England Journal of Medicine is simply this: CIRM funding of a competitive grant took a mouse discovery of the CD47 ‘don’t eat me’ signal through all preclinical work to and through a phase 1 IND with the FDA. Our National Institutes of Health (NIH) did not fund any part of the clinical trial or preclinical run up to the trial, so it is fortunate for those patients and those that will follow, if the treatment continues its success in larger trials, that California voters took the state’s right action to fund research not funded by the federal government.”

Dr. Maria Millan, CIRM’s President & CEO, says the deal is a perfect example of CIRM’s value to the field of regenerative medicine and our ability to work with our grantees to make them as successful as possible.

“To say this is incredible would be an understatement! Words cannot describe how excited we are that this novel approach to battling currently untreatable malignancies has the prospect of making it to patients in need and this is a major step. Speaking on behalf of CIRM, we are very honored to have been a partner with Forty Seven Inc. from the very beginning.

CIRM Senior Science Officer, Dr. Ingrid Caras, was part of the team that helped a group of academic scientists take their work out of the lab and into the real world.

“I had the pleasure of working with and helping the Stanford team since CIRM provided the initial funding to translate the idea of developing CD47 blockade as a therapeutic approach. This was a team of superb scientists who we were fortunate to work closely with them to navigate the Regulatory environment and develop a therapeutic product. We were able to provide guidance as well as funding and assist in the ultimate success of this project.”

Forty Seven Inc. is far from the only example of this kind of support and collaboration. We have always seen ourselves as far more than just a funding agency. Money is important, absolutely. But so too is bringing the experience and expertise of our team to help academic scientists take a promising idea and turn it into a successful therapy.

After all that’s what our mission is, doing all we can to accelerate stem cell therapies to patients with unmet medical needs. And after a deal like this, Forty Seven Inc. is definitely accelerating its work.

Donor blood stem cells and T cells could help patients wean off immunosuppressive drugs after organ transplant

Dr. Samuel Strober is refining a process that eliminates the need for the many immunosuppresant drugs normally required after a transplant.
Image credit: Stanford Medicine News Center

In 2019, there were over 23,000 kidney transplants in the United States, according to figures from the United Network for Organ Sharing (UNOS). These transplants can be lifesaving, but the donated organ can be perceived as a foreign invader by the patient’s immune system and attacked. In order to protect the organ from attack, transplant recipients are required to take numerous drugs that suppress the immune system, which are referred to as immunosupressive (IS) drugs. Unfortunately, these drugs, while helping protect the organ, can also cause long term problems such as hypertension, diabetes, heart disease, infection, a high concentration of fats in the blood, and cancer.

To address this problem, Dr. Samuel Strober and his team at Stanford University are conducting a CIRM-funded clinical trial that gives patients getting a kidney transplant a mixture of their own blood cells and cells from the kidney donor, a process called mixed chimerism.

Pairing patients and donors for transplants is done via Human Leukocyte Antigen (HLA) matching. HLA are markers on most cells in your body and are used by your immune system to recognize which cells belong to the body. If you are fully HLA matched that means your cells and the donor cells are immunologically compatible, and so less likely to be rejected. If they are HLA haplotypes, it means they are close but not fully matched so rejection is more likely.

In the trial, fifty-one patients with end stage renal failure that had just received a kidney transplant were infused with blood stem cells (cells that can give rise to different kind of blood cells) and T cells (a cell that plays a role in the immune response) obtained from the donor to achieve a mixed chimerism. Of the 51 patients 29 were fully HLA matched, and 22 were HLA haplotype matched.

Standard IS drugs were administered to all the patients after transplantation and the patients were monitored from six to twelve months to ensure there was no organ rejection or graft vs host disease (GVHD), a condition where donated blood stem cells attack the body.

After this period, the patients were taken off the IS drugs and the results of this trial are very promising. Twenty-four of the fully HLA matched patients with a persistent mixed chimerism for at least six months were able to stop taking the IS drugs without evidence of rejection for at least two years. Ten HLA haplotype matched patients with a persistent mixed chimerism for at least twelve months were able to stop taking some of the IS drugs without rejection.

This is encouraging news for patients undergoing any kind of transplant, leading to hope that one day all patients might be able to get a life-saving organ without having to take the IS drugs forever.

The full results of this study were published in Science Translational Medicine.

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.

 

Facebook Live: Ask the Stem Cell Team

On December 12th we hosted our latest ‘Facebook Live: Ask the Stem Cell Team’ event. This time around we really did mean team. We had a host of our Science Officers answering questions from friends and supporters of CIRM. We got a lot of questions and didn’t have enough time to address them all. So here’s answers to all the questions.

What are the obstacles to using partial cellular reprogramming to return people’s entire bodies to a youthful state. Paul Hartman.  San Leandro, California

Dr. Kelly Shepard

Dr. Kelly Shepard: Certainly, scientists have observed that various manipulations of cells, including reprogramming, partial reprogramming, de-differentiation and trans-differentiation, can restore or change properties of cells, and in some cases, these changes can reflect a more “youthful” state, such as having longer telomeres, better proliferative capacity, etc. However, some of these same rejuvenating properties, outside of their normal context, could be harmful or deadly, for example if a cell began to grow and divide when or where it shouldn’t, similar to cancer. For this reason, I believe the biggest obstacles to making this approach a reality are twofold: 1)  our current, limited understanding of the nature of partially reprogrammed cells; and 2) our inability to control the fate of those cells that have been partially reprogrammed, especially if they are inside a living organism.  Despite the challenges, I think there will be step wise advances where these types of approaches will be applied, starting with specific tissues. For example, CIRM has recently funded an approach that uses reprogramming to make “rejuvenated” versions of T cells for fighting lung cancer.  There is also a lot of interest in using such approaches to restore the reparative capacity of aged muscle. Perhaps some successes in these more limited areas will be the basis for expanding to a broader use.

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STROKE

What’s going on with Stanford’s stem cell trials for stroke? I remember the first trial went really well In 2016 have not heard anything about since? Elvis Arnold

Dr. Lila Collins

Dr. Lila Collins: Hi Elvis, this is an evolving story.  I believe you are referring to SanBio’s phase 1/2a stroke trial, for which Stanford was a site. This trial looked at the safety and feasibility of SanBio’s donor or allogeneic stem cell product in chronic stroke patients who still had motor deficits from their strokes, even after completing physical therapy when natural recovery has stabilized.  As you note, some of the treated subjects had promising motor recoveries. 

SanBio has since completed a larger, randomized phase 2b trial in stroke, and they have released the high-level results in a press release.  While the trial did not meet its primary endpoint of improving motor deficits in chronic stroke, SanBio conducted a very similar randomized trial in patients with stable motor deficits from chronic traumatic brain injury (TBI).  In this trial, SanBio saw positive results on motor recovery with their product.  In fact, this product is planned to move towards a conditional approval in Japan and has achieved expedited regulatory status in the US, termed RMAT, in TBI which means it could be available more quickly to patients if all goes well.  SanBio plans to continue to investigate their product in stroke, so I would stay tuned as the work unfolds. 

Also, since you mentioned Stanford, I should note that Dr Gary Steinberg, who was a clinical investigator in the SanBio trial you mentioned, will soon be conducting a trial with a different product that he is developing, neural progenitor cells, in chronic stroke.  The therapy looks promising in preclinical models and we are hopeful it will perform well for patients in the clinic.

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I am a stroke survivor will stem cell treatment able to restore my motor skills? Ruperto

Dr. Lila Collins:

Hi Ruperto. Restoring motor loss after stroke is a very active area of research.  I’ll touch upon a few ongoing stem cell trials.  I’d just like to please advise that you watch my colleague’s comments on stem cell clinics (these can be found towards the end of the blog) to be sure that any clinical research in which you participate is as safe as possible and regulated by FDA.

Back to stroke, I mentioned SanBio’s ongoing work to address motor skill loss in chronic stroke earlier.  UK based Reneuron is also conducting a phase 2 trial, using a neural progenitor cell as a candidate therapy to help recover persistent motor disability after stroke (chronic).  Dr Gary Steinberg at Stanford is also planning to conduct a clinical trial of a human embryonic stem cell-derived neuronal progenitor cell in stroke.

There is also promising work being sponsored by Athersys in acute stroke. Athersys published results from their randomized, double blinded placebo controlled Ph2 trial of their Multistem product in patients who had suffered a stroke within 24-48 hours.  After intravenous delivery, the cells improved a composite measure of stroke recovery, including motor recovery.  Rather than acting directly on the brain, Multistem seems to work by traveling to the spleen and reducing the inflammatory response to a stroke that can make the injury worse.

Athersys is currently recruiting a phase 3 trial of its Multistem product in acute stroke (within 1.5 days of the stroke).  The trial has an accelerated FDA designation, called RMAT and a special protocol assessment.  This means that if the trial is conducted as planned and it reaches the results agreed to with the FDA, the therapy could be cleared for marketing.  Results from this trial should be available in about two years. 

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Questions from several hemorrhagic stroke survivors who say most clinical trials are for people with ischemic strokes. Could stem cells help hemorrhagic stroke patients as well?

Dr. Lila Collins:

Regarding hemorrhagic stroke, you are correct the bulk of cell therapies for stroke target ischemic stroke, perhaps because this accounts for the vast bulk of strokes, about 85%.

That said, hemorrhagic strokes are not rare and tend to be more deadly.  These strokes are caused by bleeding into or around the brain which damages neurons.  They can even increase pressure in the skull causing further damage.  Because of this the immediate steps treating these strokes are aimed at addressing the initial bleeding insult and the blood in the brain.

While most therapies in development target ischemic stroke, successful therapies developed to repair neuronal damage or even some day replace lost neurons, could be beneficial after hemorrhagic stroke as well.

We are aware of a clinical trial targeting acute hemorrhagic stroke that is being run by the Mayo clinic in Jacksonville Florida.

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I had an Ischemic stroke in 2014, and my vision was also affected. Can stem cells possibly help with my vision issues. James Russell

Dr. Lila Collins:

Hi James. Vision loss from stroke is complex and the type of loss depends upon where the stroke occurred (in the actual eye, the optic nerve or to the other parts of the brain controlling they eye or interpreting vision).  The results could be:

  1. Visual loss from damage to the retina
  2. You could have a normal eye with damage to the area of the brain that controls the eye’s movement
  3. You could have damage to the part of the brain that interprets vision.

You can see that to address these various issues, we’d need different cell replacement approaches to repair the retina or the parts of the brain that were damaged. 

Replacing lost neurons is an active effort that at the moment is still in the research stages.  As you can imagine, this is complex because the neurons have to make just the right connections to be useful. 

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VISION

Is there any stem cell therapy for optical nerve damage? Deanna Rice

Dr. Ingrid Caras

Dr. Ingrid Caras: There is currently no proven stem cell therapy to treat optical nerve damage, even though there are shady stem cell clinics offering treatments.  However, there are some encouraging early gene therapy studies in mice using a virus called AAV to deliver growth factors that trigger regeneration of the damaged nerve. These studies suggest that it may be possible to restore at least some visual function in people blinded by optic nerve damage from glaucoma

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I read an article about ReNeuron’s retinitis pigmentosa clinical trial update.  In the article, it states: “The company’s treatment is a subretinal injection of human retinal progenitors — cells which have almost fully developed into photoreceptors, the light-sensing retinal cells that make vision possible.” My question is: If they can inject hRPC, why not fully developed photoreceptors? Leonard

Dr. Kelly Shepard: There is evidence from other studies, including from other tissue types such as blood, pancreas, heart and liver, that fully developed (mature) cell types tend not to engraft as well upon transplantation, that is the cells do not establish themselves and survive long term in their new environment. In contrast, it has been observed that cells in a slightly less “mature” state, such as those in the progenitor stage, are much more likely to establish themselves in a tissue, and then differentiate into more mature cell types over time. This question gets at the crux of a key issue for many new therapies, i.e. what is the best cell type to use, and the best timing to use it.

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My question for the “Ask the Stem Cell Team” event is: When will jCyte publish their Phase IIb clinical trial results. Chris Allen

Dr. Ingrid Caras: The results will be available sometime in 2020.

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I understand the hRPC cells are primarily neurotropic (rescue/halt cell death); however, the literature also says hRPC can become new photoreceptors.  My questions are: Approximately what percentage develop into functioning photoreceptors? And what percentage of the injected hRPC are currently surviving? Leonard Furber, an RP Patient

Dr. Kelly Shepard: While we can address these questions in the lab and in animal models, until there is a clinical trial, it is not possible to truly recreate the environment and stresses that the cells will undergo once they are transplanted into a human, into the site where they are expected to survive and function. Thus, the true answer to this question may not be known until after clinical trials are performed and the results can be evaluated. Even then, it is not always possible to monitor the fate of cells after transplantation without removing tissues to analyze (which may not be feasible), or without being able to transplant labeled cells that can be readily traced.

Dr. Ingrid Caras – Although the cells have been shown to be capable of developing into photoreceptors, we don’t know if this actually happens when the cells are injected into a patient’s eye.   The data so far suggest that the cells work predominantly by secreting growth factors that rescue damaged retinal cells or even reverse the damage. So one possible outcome is that the cells slow or prevent further deterioration of vision. But an additional possibility is that damaged retinal cells that are still alive but are not functioning properly may become healthy and functional again which could result in an improvement in vision.

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DIABETES

What advances have been made using stem cells for the treatment of Type 2 Diabetes? Mary Rizzo

Dr. Ross Okamura

Dr. Ross Okamura: Type 2 Diabetes (T2D) is a disease where the body is unable to maintain normal glucose levels due to either resistance to insulin-regulated control of blood sugar or insufficient insulin production from pancreatic beta cells.  The onset of disease has been associated with lifestyle influenced factors including body mass, stress, sleep apnea and physical activity, but it also appears to have a genetic component based upon its higher prevalence in certain populations. 

Type 1 Diabetes (T1D) differs from T2D in that in T1D patients the pancreatic beta cells have been destroyed by the body’s immune system and the requirement for insulin therapy is absolute upon disease onset rather than gradually developing over time as in many T2D cases.  Currently the only curative approach to alleviate the heavy burden of disease management in T1D has been donor pancreas or islet transplantation. However, the supply of donor tissue is small relative to the number of diabetic patients.  Donor islet and pancreas transplants also require immune suppressive drugs to prevent allogenic immune rejection and the use of these drugs carry additional health concerns.  However, for some patients with T1D, especially those who may develop potentially fatal hypoglycemia, immune suppression is worth the risk.

To address the issue of supply, there has been significant activity in stem cell research to produce insulin secreting beta cells from pluripotent stem cells and recent clinical data from Viacyte’s CIRM funded trial indicates that implanted allogeneic human stem cell derived cells in T1D patients can produce circulating c-peptide, a biomarker for insulin.  While the trial is not designed specifically to cure insulin-dependent T2D patients, the ability to produce and successfully engraft stem cell-derived beta cells would be able to help all insulin-dependent diabetic patients.

It’s also worth noting that there is a sound scientific reason to clinically test a patient-derived pluripotent stem cell-based insulin-producing cells in insulin-dependent T2D diabetic patients; the cells in this case could be evaluated for their ability to cure diabetes in the absence of needing to prevent both allogeneic and autoimmune responses.

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SPINAL CORD INJURY

Is there any news on clinical trials for spinal cord injury? Le Ly

Kevin McCormack: The clinical trial CIRM was funding, with Asterias (now part of a bigger company called Lineage Cell Therapeutics, is now completed and the results were quite encouraging. In a news release from November of 2019 Brian Culley, CEO of Lineage Cell Therapeutics, described the results this way.

“We remain extremely excited about the potential for OPC1 (the name of the therapy used) to provide enhanced motor recovery to patients with spinal cord injuries. We are not aware of any other investigative therapy for SCI (spinal cord injury) which has reported as encouraging clinical outcomes as OPC1, particularly with continued improvement beyond 1 year. Overall gains in motor function for the population assessed to date have continued, with Year 2 assessments measuring the same or higher than at Year 1. For example, 5 out of 6 Cohort 2 patients have recovered two or more motor levels on at least one side as of their Year 2 visit whereas 4 of 6 patients in this group had recovered two motor levels as of their Year 1 visit. To put these improvements into perspective, a one motor level gain means the ability to move one’s arm, which contributes to the ability to feed and clothe oneself or lift and transfer oneself from a wheelchair. These are tremendously meaningful improvements to quality of life and independence. Just as importantly, the overall safety of OPC1 has remained excellent and has been maintained 2 years following administration, as measured by MRI’s in patients who have had their Year 2 follow-up visits to date. We look forward to providing further updates on clinical data from SCiStar as patients continue to come in for their scheduled follow up visits.”

Lineage Cell Therapeutics plans to meet with the FDA in 2020 to discuss possible next steps for this therapy.

In the meantime the only other clinical trial I know that is still recruiting is one run by a company called Neuralstem. Here is a link to information about that trial on the www.clinicaltrials.gov website.

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ALS

Now that the Brainstorm ALS trial is finished looking for new patients do you have any idea how it’s going and when can we expect to see results? Angela Harrison Johnson

Dr. Ingrid Caras: The treated patients have to be followed for a period of time to assess how the therapy is working and then the data will need to be analyzed.  So we will not expect to see the results probably for another year or two.

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AUTISM

Are there treatments for autism or fragile x using stem cells? Magda Sedarous

Dr. Kelly Shepard: Autism and disorders on the autism spectrum represent a collection of many different disorders that share some common features, yet have different causes and manifestations, much of which we still do not understand. Knowing the origin of a disorder and how it affects cells and systems is the first step to developing new therapies. CIRM held a workshop on Autism in 2009 to brainstorm potential ways that stem cell research could have an impact. A major recommendation was to exploit stem cells and new technological advances to create cells and tissues, such as neurons, in the lab from autistic individuals that could then be studied in great detail.  CIRM followed this recommendation and funded several early-stage awards to investigate the basis of autism, including Rett Syndrome, Fragile X, Timothy Syndrome, and other spectrum disorders. While these newer investigations have not yet led to therapies that can be tested in humans, this remains an active area of investigation. Outside of CIRM funding, we are aware of more mature studies exploring the effects of umbilical cord blood or other specific stem cell types in treating autism, such as an ongoing clinical trial conducted at Duke University.

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PARKINSON’S DISEASE

What is happening with Parkinson’s research? Hanifa Gaphoor

Dr. Kent Fitzgerald

Dr. Kent Fitzgerald: Parkinson’s disease certainly has a significant amount of ongoing work in the regenerative medicine and stem cell research. 

The nature of cell loss in the brain, specifically the dopaminergic cells responsible for regulating the movement, has long been considered a good candidate for cell replacement therapy.  

This is largely due to the hypothesis that restoring function to these cells would reverse Parkinson’s symptoms. This makes a lot of sense as front line therapy for the disease for many years has been dopamine replacement through L-dopa pills etc.  Unfortunately, over time replacing dopamine through a pill loses its benefit, whereas replacing or fixing the cells themselves should be a more permanent fix. 

Because a specific population of cells in one part of the brain are lost in the disease, multiple labs and clinicians have sought to replace or augment these cells by transplantation of “new” functional cells able to restore function to the area an theoretically restore voluntary motor control to patients with Parkinson’s disease. 

Early clinical research showed some promise, however also yielded mixed results, using fetal tissue transplanted into the brains of Parkinson’s patients.   As it turns out, the cell types required to restore movement and avoid side effects are somewhat nuanced.  The field has moved away from fetal tissue and is currently pursuing the use of multiple stem cell types that are driven to what is believed to be the correct subtype of cell to repopulate the lost cells in the patient. 

One project CIRM sponsored in this area with Jeanne Loring sought to develop a cell replacement therapy using stem cells from the patients themselves that have been reprogrammed into the kinds of cell damaged by Parkinson’s.  This type of approach may ultimately avoid issues with the cells avoiding rejection by the immune system as can be seen with other types of transplants (i.e. liver, kidney, heart etc).

Still, others are using cutting edge gene therapy technology, like the clinical phase project CIRM is sponsoring with Krystof Bankiewicz to investigate the delivery of a gene (GDNF) to the brain that may help to restore the activity of neurons in the Parkinson’s brain that are no longer working as they should. 

The bulk of the work in the field of PD at the present remains centered on replacing or restoring the dopamine producing population of cells in the brain that are affected in disease.   

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HUNTINGTON’S DISEASE

Any plans for Huntington’s? Nikhat Kuchiki

Dr. Lisa Kadyk

Dr. Lisa Kadyk: The good news is that there are now several new therapeutic approaches to Huntington’s Disease that are at various stages of preclinical and clinical development, including some that are CIRM funded.   One CIRM-funded program led by Dr. Leslie Thompson at UC Irvine is developing a cell-based therapeutic that consists of neural stem cells that have been manufactured from embryonic stem cells.   When these cells are injected into the brain of a mouse that has a Huntington’s Disease mutation, the cells engraft and begin to differentiate into new neurons.  Improvements are seen in the behavioral and electrophysiological deficits in these mutant mice, suggesting that similar improvements might be seen in people with the disease.   Currently, CIRM is funding Dr. Thompson and her team to carry out rigorous safety studies in animals using these cells, in preparation for submitting an application to the FDA to test the therapy in human patients in a clinical trial.   

There are other, non-cell-based therapies also being tested in clinical trials now, using  anti-sense oligonucleotides (Ionis, Takeda) to lower the expression of the Huntington protein.  Another HTT-lowering approach is similar – but uses miRNAs to lower HTT levels (UniQure, Voyager)

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TRAUMATIC BRAIN INJURY (TBI)

My 2.5 year old son recently suffered a hypoxic brain injury resulting in motor and speech disabilities. There are several clinical trials underway for TBI in adults. My questions are:

  • Will the results be scalable to pediatric use and how long do you think it would take before it is available to children?
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  • I’m wondering why the current trials have chosen to go the route of intracranial injections as opposed to something slightly less invasive like an intrathecal injection?
  • Is there a time window period in which stem cells should be administered by, after which the administration is deemed not effective?

Dr. Kelly Shepard:  TBI and other injuries of the nervous system are characterized by a lot of inflammation at the time of injury, which is thought to interfere with the healing process- and thus some approaches are intended to be delivered after that inflammation subsides. However, we are aware of approaches that intend to deliver a therapy to a chronic injury, or one that has occurred  previously. Thus, the answer to this question may depend on how the intended therapy is supposed to work. For example, is the idea to grow new neurons, or is it to promote the survival of neurons of other cells that were spared by the injury? Is the therapy intended to address a specific symptom, such as seizures? Is the therapy intended to “fill a gap” left behind after inflammation subsides, which might not restore all function but might ameliorate certain symptoms.? There is still a lot we don’t understand about the brain and the highly sophisticated network of connections that cannot be reversed by only replacing neurons, or only reducing inflammation, etc. However, if trials are well designed, they should yield useful information even if the therapy is not as effective as hoped, and this information will pave the way to newer approaches and our technology and understanding evolves.

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We have had a doctor recommending administering just the growth factors derived from MSC stem cells. Does the science work that way? Is it possible to isolate the growth factors and boost the endogenous growth factors by injecting allogenic growth factors?

Dr. Stephen Lin

Dr. Stephen Lin:  Several groups have published studies on the therapeutic effects in non-human animal models of using nutrient media from MSC cultures that contain secreted factors, or extracellular vesicles from cells called exosomes that carry protein or nucleic acid factors.  Scientifically it is possible to isolate the factors that are responsible for the therapeutic effect, although to date no specific factor or combination of factors have been identified to mimic the effects of the undefined mixtures in the media and exosomes.  At present no regulatory approved clinical therapy has been developed using this approach. 

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PREDATORY STEM CELL CLINICS

What practical measures are being taken to address unethical practitioners whose bad surgeries are giving stem cell advances a bad reputation and are making forward research difficult? Kathy Jean Schultz

Dr. Geoff Lomax

Dr. Geoff Lomax: Terrific question! I have been doing quite a bit research into the history of this issue of unethical practitioners and I found an 1842 reference to “quack medicines.” Clearly this is nothing new. In that day, the author appealed to make society “acquainted with the facts.”

In California, we have taken steps to (1) acquaint patients with the facts about stem cell treatments and (2) advance FDA authorized treatments for unmet medical needs.

  • First, CIRM work with Senator Hernandez in 2017 to write a law the requires provides to disclose to patient that a stem cell therapy has not been approved by the Food and Drug administration.
  • We continue to work with the State Legislature and Medical Board of California to build on policies that require accurate disclosure of the facts to patients.
  • Second, our clinical trial network the — Alpha Stem Cell Clinics – have supported over 100 FDA-authorized clinical trials to advance responsible clinical research for unmet medical needs.

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I’m curious if adipose stem cell being used at clinics at various places in the country is helpful or beneficial? Cheri Hicks

Adipose tissue has been widely used particularly in plastic and reconstructive surgery. Many practitioners suggest adipose cells are beneficial in this context. With regard to regenerative medicine and / or the ability to treat disease and injury, I am not aware of any large randomized clinical trials that demonstrate the safety and efficacy of adipose-derived stem cells used in accordance with FDA guidelines.

I went to a “Luncheon about Stem Cell Injections”. It sounded promising. I went thru with it and got the injections because I was desperate from my knee pain. The price of stem cell injections was $3500 per knee injection. All went well. I have had no complications, but haven’t noticed any real major improvement, and here I am a year later. My questions are:

 1) I wonder on where the typical injection cells are coming from?

  2) I wonder what is the actual cost of the cells?

3) What kind of results are people getting from all these “pop up” clinics or established clinics that are adding this to there list of offerings?

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Dr. Geoff Lomax: You raise a number of questions and point here; they are all very good and it’s is hard to give a comprehensive response to each one, but here is my reaction:

  • There are many practitioners in the field of orthopedics who sincerely believe in the potential of cell-based treatments to treat injury / pain
  • Most of the evidence presented is case reports that individuals have benefited
  • The challenge we face is not know the exact type of injury and cell treatments used.
  • Well controlled clinical trials would really help us understand for what cells (or cell products) and for what injury would be helpful
  • Prices of $3000 to $5000 are not uncommon, and like other forms of private medicine there is often a considerable mark-up in relation to cost of goods.
  • You are correct that there have not been reports of serious injury for knee injections
  • However the effectiveness is not clear while simultaneously millions of people have been aided by knee replacements.

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Do stem cells have benefits for patients going through chemotherapy and radiation therapy? Ruperto

Dr. Kelly Shepard: The idea that a stem cell therapy could help address effects of chemotherapy or radiation is being and has been pursued by several investigators over the years, including some with CIRM support. Towards the earlier stages, people are looking at the ability of different stem cell-derived neural cell preparations to replace or restore function of certain brain cells that are damaged by the effects of chemotherapy or radiation. In a completely different type of approach, a group at City of Hope is exploring whether a bone marrow transplant with specially modified stem cells can provide a protective effect against the chemotherapy that is used to treat a form of brain cancer, glioblastoma. This study is in the final stage of development that, if all goes well, culminates with application to the FDA to allow initiation of a clinical trial to test in people.

Dr. Ingrid Caras: That’s an interesting and valid question.  There is a Phase 1 trial ongoing that is evaluating a novel type of stem/progenitor cell from the umbilical cord of healthy deliveries.  In animal studies, these cells have been shown to reduce the toxic effects of chemotherapy and radiation and to speed up recovery. These cells are now being tested in a First-in-human clinical trial in patients who are undergoing high-dose chemotherapy to treat their disease.

There is a researcher at Stanford, Michelle Monje, who is investigating that the role of damage to stem cells in the cognitive problems that sometimes arise after chemo- and radiation therapy (“chemobrain”).  It appears that damage to stem cells in the brain, especially those responsible for producing oligodendrocytes, contributes to chemobrain.  In CIRM-funded work, Dr. Monje has identified small molecules that may help prevent or ameliorate the symptoms of chemobrain.

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Is it possible to use a technique developed to fight one disease to also fight another? For instance, the bubble baby disease, which has cured (I think) more than 50 children, may also help fight sickle cell anemia?  Don Reed.

Dr. Lisa Kadyk: Hi Don. Yes, the same general technique can often be applied to more than one disease, although it needs to be “customized” for each disease.   In the example you cite, the technique is an “autologous gene-modified bone marrow transplant” – meaning the cells come from the patient themselves.  This technique is relevant for single gene mutations that cause diseases of the blood (hematopoietic) system.  For example, in the case of “bubble baby” diseases, a single mutation can cause failure of immune cell development, leaving the child unable to fight infections, hence the need to have them live in a sterile “bubble”.   To cure that disease, blood stem cells, which normally reside in the bone marrow, are collected from the patient and then a normal version of the defective gene is introduced into the cells, where it is incorporated into the chromosomes.   Then, the corrected stem cells are transplanted back into the patient’s body, where they can repopulate the blood system with cells expressing the normal copy of the gene, thus curing the disease.  

A similar approach could be used to treat sickle cell disease, since it is also caused by a single gene mutation in a gene (beta hemoglobin) that is expressed in blood cells.  The same technique would be used as I described for bubble baby disease but would differ in the gene that is introduced into the patient’s blood stem cells. 

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Is there any concern that CIRM’s lack of support in basic research will hamper the amount of new approaches that can reach clinical stages? Jason

Dr. Kelly Shepard: CIRM always has and continues to believe that basic research is vital to the field of regenerative medicine. Over the past 10 years CIRM has invested $904 million in “discovery stage/basic research”, and about $215 million in training grants that supported graduate students, post docs, clinical fellows, undergraduate, masters and high school students performing basic stem cell research. In the past couple of years, with only a limited amount of funds remaining, CIRM made a decision to invest most of the remaining funds into later stage projects, to support them through the difficult transition from bench to bedside. However, even now, CIRM continues to sponsor some basic research through its Bridges and SPARK Training Grant programs, where undergraduate, masters and even high school students are conducting stem cell research in world class stem cell laboratories, many of which are the same laboratories that were supported through CIRM basic research grants over the past 10 years. While basic stem cell research continues to receive a substantial level of support from the NIH ($1.8 billion in 2018, comprehensively on stem cell projects) and other funders, CIRM believes continued support for basic research, especially in key areas of stem cell research and vital opportunities, will always be important for discovering and developing new treatments.

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What is the future of the use of crispr cas9 in clinical trials in california/globally. Art Venegas

Dr. Kelly Shepard: CRISPR/Cas9 is a powerful gene editing tool. In only a few years, CRISPR/Cas9 technology has taken the field by storm and there are already a few CRISPR/Cas9 based treatments being tested in clinical trials in the US. There are also several new treatments that are at the IND enabling stage of development, which is the final testing stage required by the FDA before a clinical trial can begin. Most of these clinical trials involving CRISPR go through an “ex vivo” approach, taking cells from the patient with a disease causing gene, correcting the gene in the laboratory using CRISPR, and reintroducing the cells carrying the corrected gene back into the patient for treatment.  Sickle cell disease is a prime example of a therapy being developed using this strategy and CIRM funds two projects that are preparing for clinical trials with this approach.  CRISPR is also being used to develop the next generation of cancer T-cell therapies (e.g. CAR-T), where T-cells – a vital part of our immune system – are modified to target and destroy cancer cell populations.  Using CRISPR to edit cells directly in patients “in vivo” (inside the body) is far less common currently but is also being developed.  It is important to note that any FDA sanctioned “in vivo” CRISPR clinical trial in people will only modify organ-specific cells where the benefits cannot be passed on to subsequent generations. There is a ban on funding for what are called germ line cells, where any changes could be passed down to future generations.

CIRM is currently supporting multiple CRISPR/Cas9 gene editing projects in California from the discovery or most basic stage of research, through the later stages before applying to test the technique in people in a clinical trial.

While the field is new – if early safety signals from the pioneering trials are good, we might expect a number of new CRISPR-based approaches to enter clinical testing over the next few years. The first of these will will likely be in the areas of bone marrow transplant to correct certain blood/immune or  metabolic diseases, and cancer immunotherapies, as these types of approaches are the best studied and furthest along in the pipeline.

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Explain the differences between gene therapy and stem cell therapy? Renee Konkol

Dr. Stephen Lin:  Gene therapy is the direct modification of cells in a patient to treat a disease.  Most gene therapies use modified, harmless viruses to deliver the gene into the patient.  Gene therapy has recently seen many success in the clinic, with the first FDA approved therapy for a gene induced form of blindness in 2017 and other approvals for genetic forms of smooth muscle atrophy and amyloidosis. 

Stem cell therapy is the introduction of stem cells into patients to treat a disease, usually with the purpose of replacing damaged or defective cells that contribute to the disease.  Stem cell therapies can be derived from pluripotent cells that have the potential to turn into any cell in the body and are directed towards a specific organ lineage for the therapy.  Stem cell therapies can also be derived from other cells, called progenitors, that have the ability to turn into a limited number of other cells in the body. for example hematopoietic or blood stem cells (HSCs), which are found in bone marrow, can turn into other cells of the blood system including B-cells and T-cells: while mesenchymal stem cells (MSCs), which are usually found in fat tissue, can turn into bone, cartilage, and fat cells.  The source of these cells can be from the patient’s own body (autologous) or from another person (allogeneic).

Gene therapy is often used in combination with cell therapies when cells are taken from the patient and, in the lab, modified genetically to correct the mutation or to insert a correct form of the defective gene, before being returned to patients.  Often referred to as “ex vivo gene therapy” – because the changes are made outside the patient’s body – these therapies include Chimeric Antigen Receptor T (CAR-T) cells for cancer therapy and gene modified HSCs to treat blood disorders such as severe combined immunodeficiency and sickle cell disease. This is an exciting area that has significantly improved and even cured many people already.

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Currently, how can the outcome of CIRM stem cell medicine projects and clinical trials be soundly interpreted when their stem cell-specific doses are not known? James L. Sherley, M.D., Ph.D., Director. Asymmetrex, LLC

Dr. Stephen Lin:  Stem cell therapies that receive approval to conduct clinical trials must submit a package of data to the FDA that includes studies that demonstrate their effectiveness, usually in animal models of the disease that the cell therapy is targeting.  Those studies have data on the dose of the cell therapy that creates the therapeutic effect, which is used to estimate cell doses for the clinical trial.  CIRM funds discovery and translational stage awards to conduct these types of studies to prepare cell therapies for clinical trials.  The clinical trial is also often designed to test multiple doses of the cell therapy to determine the one that has the best therapeutic effect.   Dosing can be very challenging with cell therapies because of issues including survival, engraftment, and immune rejection, but CIRM supports studies designed to provide data to give the best estimate possible.

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Is there any research on using stem cells to increase the length of long bones in people?” For example, injecting stem cells into the growth plates to see if the cells can be used to lengthen limbs. Sajid

Dr. Kelly Shepard: There is quite a lot of ongoing research seeking ways to repair bones with stem cell based approaches, which is not the same but somewhat related. Much of this is geared towards repairing the types of bone injuries that do not heal well naturally on their own (large gaps, dead bone lesions, degenerative bone conditions). Also, a lot of this research involves engineering bone tissues in the lab and introducing the engineered tissue into a bone lesion that need be repaired. What occurs naturally at the growth plate is a complex interaction between many different cell types, much of which we do not fully understand. We do not fully understand how to use the cells that are used to engineer bone tissue in the lab. However, a group at Stanford, with some CIRM support, recently discovered a “skeletal stem cell” that exists naturally at the ends of human bones and at sites of fracture.  These are quite different than MSCs and offer a new path to be explored for repairing and generating bone. 

Two CIRM supported studies highlighted in Nature as promising approaches for blood disorders

Blood stem cells (blue) are cleared from the bone marrow (purple) before new stem cells can be transplanted.Credit: Dennis Kunkel Microscopy/SPL

Problems with blood stem cells, a type of stem cell in your bone marrow that gives rise to various kinds of blood cells, can sometimes result in blood cancer as well as genetic and autoimmune diseases.

It is because of this that researchers have looked towards blood stem cell transplants, which involves replacing a person’s defective blood stem cells with healthy ones take from either a donor or the patient themselves.

However, before this can be done, the existing population of defective stem cells must be eradicated in order to allow the transplanted blood stem cells to properly anchor themselves into the bone marrow. Current options for this include full-body radiation or chemotherapy, but these approaches are extremely toxic.

But what if there was a way to selectively target these blood stem cells in order to make the transplants much safer?

An article published in Nature highlights the advancements made in the field of blood stem cell transplantation, some of which is work that is funded by yours truly.

One of the approaches highlighted involves the work that we funded related to Forty Seven and an antibody created that inhibits a protein called CD47.

The article discusses how Forty Seven tested two antibodies in monkeys. One antibody blocks the activity of a molecule called c-Kit, which is found on blood stem cells. The other is the antibody that blocks CD47, which is found on some immune cells. Inhibiting CD47 allows those immune cells to sweep up the stem cells that were targeted by the c-Kit antibody, thereby boosting its effectiveness. In early tests, the two antibodies used together reduced the number of blood stem cells in bone marrow. The next step for this team is to demonstrate that the treatment clears out the old supply of stem cells well enough to allow transplanted cells to flourish.

You can read more about the CD47 antibody in a previous blog post.

Another notable segment of this article is the CIRM funded trial that is being conducted by Dr. Judith Shizuru at Stanford University. This clinical trial also uses an antibody that targets c-Kit found on blood stem cells.

The purpose of this trial is to wipe out the problematic blood stem cells in infants with X-linked Severe combined immunodeficiency (SCID), a rare fatal genetic disorder that leaves infants without a functional immune system, in order to introduce properly functioning blood stem cells. Dr. Shizuru and her team found that transplanted blood stem cells, in this case from donors who did not have the disease, successfully took hold in the bone marrow of four out of six of the babies.

You can read more about Dr. Shizuru’s work in a previous blog post as well.

What is IPEX syndrome? A deeper dive into a CIRM funded award

Brian Lookofsky (left) and his son Taylor Lookofsky (right) at the CIRM Board meeting on October 31, 2019. Taylor is living with IPEX syndrome.

Last week we shared a powerful story of patient advocate Taylor Lookofsky, a young man with IPEX syndrome. In his speech, he talked about the impact the condition has had on his life. Taylor shared this speech a few weeks ago right after the CIRM Board awarded $5.53 million to Dr. Rosa Bacchetta for her work related to IPEX syndrome.

But this begs the question, what exactly is IPEX syndrome? What is the approach that Dr. Bacchetta is working on? For those of you interested in the deeper scientific dive, we will elaborate on this complex disease and promising approach.

IPEX syndrome is a rare disease that primarily affects males and is caused by a genetic mutation that leads to a lack of specialized immune cells called regulatory T cells (Tregs).

Without the presence of Tregs, a patient’s own immune cells attack the body’s own tissues and organs, a phenomenon known as autoimmunity.  This affects many different areas such as the intestines, skin, and hormone-producing glands and can be fatal in early childhood. 

Current treatment options include a bone marrow transplant and immune suppressing drugs.  However, immune suppression is only partially effective and can cause severe side effects while bone marrow transplants are limited due to lack of matching donors.

Dr. Rosa Bacchetta and her team at Stanford will take a patient’s own blood in order to obtain CD4+ T cells.  Then, using gene therapy, they will insert a normal version of the mutated gene into the CD4+ T cells, allowing them to function like normal Treg cells.  These Treg-like cells would then be reintroduced back into the patient, hopefully creating an IPEX-free blood supply and correcting the problem.

Furthermore, if successful, this treatment could be adapted for treatment of other autoimmune conditions where Treg cells are underlying problem.

The goal of this work is to complete the work necessary to conduct a clinical trial for IPEX syndrome.

Transplanted stem cells used to grow fully functional lungs in mice

Illustration of a human lung

According to organ donation statistics from the Health Resources & Services Administration, over 113,000 men, women, and children are on the national transplant waiting list as of July 2019. Another person is added to the waiting list every 10 minutes and 20 people die each day waiting for a transplant.

As these statistics highlight, there is a tremendous need for obtaining viable organs for people that are in need of a transplant. It is because of this, that scientists and researchers are exploring ways of using stem cells to potentially grow fully functional organs.

Dr. Hiromitsu Nakauchi, Stanford University

In a CIRM-supported study, Dr. Hiromitsu Nakauchi at Stanford University, in collaboration with Dr. Wellington Cardoso at Columbia University, were able to grow fully functional lungs in mouse embryos using transplanted stem cells. The full study, published in Nature Medicine, suggests that it may be possible to grow human lungs in animals and use them for patients in dire need of transplants or to study new lung treatments.

In the study, the researchers took stem cells and implanted them into modified mouse embryos that either lacked the stem cells necessary to form a lung or were not able to produce enough cells to make a lung. It was found that the implanted stem cells formed fully functional lungs that allowed the mice to live well into adulthood. Additionally, there were no signs of the mouse’s body rejecting the lung tissue composed of donor stem cells.

In a press release, Dr. Cardoso expressed optimism for the study and the potential the results hold:

“Millions of people worldwide who suffer from incurable lung diseases die without treatment due to the limited supply of donor lungs for transplantation. Our study shows that it may eventually be possible to develop new strategies for generating human lungs in animals for transplantation as an alternative to waiting for donor lungs.”