Stem Cell Agency Board Invests in 19 Discovery Research Programs Targeting Cancers, Heart Disease and Other Disorders

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Dr. Judy Shizuru, Stanford University

While stem cell and gene therapy research has advanced dramatically in recent years, there are still many unknowns and many questions remaining about how best to use these approaches in developing therapies. That’s why the governing Board of the California Institute for Regenerative Medicine (CIRM) today approved investing almost $25 million in 19 projects in early stage or Discovery research.

The awards are from CIRM’s DISC2 Quest program, which supports  the discovery of promising new stem cell-based and gene therapy technologies that could be translated to enable broad use and ultimately, improve patient care.

“Every therapy that helps save lives or change lives begins with a researcher asking a simple question, “What if?”, says Dr. Maria T. Millan, the President and CEO of CIRM. “Our Quest awards reflect the need to keep supporting early stage research, to gain a deeper understanding of stem cells work and how we can best tap into that potential to advance the field.”

Dr. Judy Shizuru at Stanford University was awarded $1.34 million to develop a safer, less-toxic form of bone marrow or hematopoietic stem cell transplant (HCT). HCT is the only proven cure for many forms of blood disorders that affect people of all ages, sexes, and races worldwide. However, current methods involve the use of chemotherapy or radiation to destroy the patient’s own unhealthy blood stem cells and make room for the new, healthy ones. This approach is toxic and complex and can only be performed by specialized teams in major medical centers, making access particularly difficult for poor and underserved communities.

Dr. Shizuru proposes developing an antibody that can direct the patient’s own immune cells to kill diseased blood stem cells. This would make stem cell transplant safer and more effective for the treatment of many life-threatening blood disorders, and more accessible for people in rural or remote parts of the country.

Lili Yang UCLA Broad Stem Cell Research Center: Photo courtesy Reed Hutchinson PhotoGraphics

Dr. Lili Yang at UCLA was awarded $1.4 million to develop an off-the-shelf cell therapy for ovarian cancer, which causes more deaths than any other cancer of the female reproductive system.

Dr. Yang is using immune system cells, called invariant natural killer T cells (iNKT) to attack cancer cells. However, these iNKT cells are only found in small numbers in the blood so current approaches involve taking those cells from the patient and, in the lab, modifying them to increase their numbers and strength before transplanting them back into the patient. This is both time consuming and expensive, and the patient’s own iNKT cells may have been damaged by the cancer, reducing the likelihood of success.

In this new study Dr. Yang will use healthy donor cord blood cells and, through genetic engineering, turn them into the specific form of iNKT cell therapy targeting ovarian cancer. This DISC2 award will support the development of these cells and do the necessary testing and studies to advance it to the translational stage.

Timothy Hoey and Tenaya Therapeutics Inc. have been awarded $1.2 million to test a gene therapy approach to replace heart cells damaged by a heart attack.

Heart disease is the leading cause of death in the U.S. with the highest incidence among African Americans. It’s caused by damage or death of functional heart muscle cells, usually due to heart attack. Because these heart muscle cells are unable to regenerate the damage is permanent. Dr. Hoey’s team is developing a gene therapy that can be injected into patients and turn their cardiac fibroblasts, cells that can contribute to scar tissue, into functioning heart muscle cells, replacing those damaged by the heart attack.

The full list of DISC2 Quest awards is:

APPLICATION NUMBERTITLE OF PROGRAMPRINCIPAL INVESTIGATORAMOUNT
  DISC2-13400  Targeted Immunotherapy-Based Blood Stem Cell Transplantation    Judy Shizuru, Stanford Universtiy  $1,341,910    
  DISC2-13505  Combating Ovarian Cancer Using Stem Cell-Engineered Off-The-Shelf CAR-iNKT Cells    Lili Yang, UCLA  $1,404,000
  DISC2-13515  A treatment for Rett syndrome using glial-restricted
neural progenitor cells  
  Alysson Muotri, UC San Diego  $1,402,240    
  DISC2-13454  Targeting pancreatic cancer stem cells with DDR1 antibodies.    Michael Karin, UC San Diego  $1,425,600  
  DISC2-13483  Enabling non-genetic activity-driven maturation of iPSC-derived neurons    Alex Savtchenko, Nanotools Bioscience  $675,000
  DISC2-13405  Hematopoietic Stem Cell Gene Therapy for Alpha
Thalassemia  
  Don Kohn, UCLA    $1,323,007  
    DISC2-13507  CAR T cells targeting abnormal N-glycans for the
treatment of refractory/metastatic solid cancers  
  Michael Demetriou, UC Irvine  $1,414,800  
  DISC2-13463  Drug Development of Inhibitors of Inflammation Using
Human iPSC-Derived Microglia (hiMG)  
  Stuart Lipton, Scripps Research Inst.  $1,658,123  
  DISC2-13390  Cardiac Reprogramming Gene Therapy for Post-Myocardial Infarction Heart Failure    Timothy Hoey, Tenaya Therapeutics  $1,215,000  
  DISC2-13417  AAV-dCas9 Epigenetic Editing for CDKL5 Deficiency Disorder    Kyle Fink, UC Davis  $1,429,378  
  DISC2-13415  Defining the Optimal Gene Therapy Approach of
Human Hematopoietic Stem Cells for the Treatment of
Dedicator of Cytokinesis 8 (DOCK8) Deficiency  
  Caroline Kuo, UCLA  $1,386,232  
  DISC2-13498  Bioengineering human stem cell-derived beta cell
organoids to monitor cell health in real time and improve therapeutic outcomes in patients  
  Katy Digovich, Minutia, Inc.  $1,198,550  
  DISC2-13469  Novel antisense therapy to treat genetic forms of
neurodevelopmental disease.  
  Joseph Gleeson, UC San Diego  $1,180,654  
  DISC2-13428  Therapeutics to overcome the differentiation roadblock in Myelodysplastic Syndrome (MDS)    Michael Bollong, Scripps Research Inst.  $1,244,160  
  DISC2-13456  Novel methods to eliminate cancer stem cells    Dinesh Rao, UCLA  $1,384,347  
  DISC2-13441  A new precision medicine based iPSC-derived model to study personalized intestinal fibrosis treatments in
pediatric patients with Crohn’s diseas  
  Robert Barrett Cedars-Sinai  $776,340
  DISC2-13512  Modified RNA-Based Gene Therapy for Cardiac
Regeneration Through Cardiomyocyte Proliferation
  Deepak Srivastava, Gladstone Institutes  $1,565,784
  DISC2-13510  An hematopoietic stem-cell-based approach to treat HIV employing CAR-T cells and anti-HIV broadly
neutralizing antibodies  
  Brian Lawson, The Scintillon Institute  $1,143,600  
  DISC2-13475  Developing gene therapy for dominant optic atrophy using human pluripotent stem cell-derived retinal organoid disease model    Xian-Jie Yang, UCLA  $1,345,691  

Stem cell agency invests in therapy using killer cells to target colorectal, breast and ovarian cancers

While there have been some encouraging advances in treating cancer in recent decades, there are still many cancers that either resist treatment or recur after treatment. Today the governing Board of the California Institute for Regenerative Medicine (CIRM) approved investing in a therapy targeting some of these hard-to-treat tumors.

BioEclipse Therapeutics Inc. was awarded nearly $8M to test a therapy using immune cells loaded with a cancer-killing virus that targets cancer tissue but spares healthy tissue.

This is the 78th clinical trial funded directly by the Stem Cell Agency.

BioEclipse combines two approaches—an immune cell called a cytokine-induced killer (CIK) cell and a virus engineered to kill cancer cells called an oncolytic virus (OV)—to create what they call “a multi-mechanistic, targeted treatment.”

They will use the patient’s own immune cells and, in the lab, combine them with the OV. The cell/virus combination will then be administered back to the patient. The job of the CIK cells is to carry the virus to the tumors. The virus is designed to specifically attack and kill tumors and stimulate the patient’s immune system to attack the tumor cells. The goal is to eradicate the primary tumor and prevent relapse and recurrence.

“With the intent to develop this treatment for chemotherapy-resistant or refractory solid tumors—including colorectal cancer, triple negative breast cancer, ovarian cancer, gastric cancer, hepatocellular carcinoma, and osteosarcoma—it addresses a significant unmet medical need in fatal conditions for which there are limited treatment options,” says Dr. Maria T. Millan, President and CEO of CIRM.  

The CIRM Board also approved more than $18 million in funding four projects under the Translation Projects program. The goal of this program is to support promising regenerative medicine (stem cell-based or gene therapy) projects that accelerate completion of translational stage activities necessary for advancement to clinical study or broad end use.

The awards went to:

ApplicationTitleInstitutionAward Amount
TRAN1-133442Optogenetic therapy for treating retinitis pigmentosa and
other inherited retinal diseases  
  Paul Bresge Ray Therapeutics Inc.  $3,999,553  
TRAN3-13332Living Synthetic Vascular Grafts with Renewable Endothelium    Aijun Wang UC Davis  $3,112,567    
TRAN1-13370Next generation affinity-tuned CAR for prostate cancer    Preet Chaudhary University of Southern California  $5,805,144  
TRAN1-3345Autologous MPO Knock-Out Hematopoietic Stem and
Progenitor Cells for Pulmonary Arterial Hypertension  
  Don Kohn UC Los Angeles  $5,207,434  

Stem Cell Agency Approves Funding for Clinical Trials Targeting Parkinson’s Disease and Blindness

The governing Board of the California Institute for Regenerative Medicine (CIRM) yesterday invested $32.92 million to fund the Stem Cell Agency’s first clinical trial in Parkinson’s disease (PD), and to support three clinical trials targeting different forms of vision loss.

This brings the total number of clinical trials funded by CIRM to 60.

The PD trial will be carried out by Dr. Krystof Bankiewicz at Brain Neurotherapy Bio, Inc. He is using a gene therapy approach to promote the production of a protein called GDNF, which is best known for its ability to protect dopaminergic neurons, the kind of cell damaged by Parkinson’s. The approach seeks to increase dopamine production in the brain, alleviating PD symptoms and potentially slowing down the disease progress.

David Higgins, PhD, a CIRM Board member and patient advocate for Parkinson’s says there is a real need for new approaches to treating the disease. In the US alone, approximately 60,000 people are diagnosed with PD each year and it is expected that almost one million people will be living with the disease by 2020.

“Parkinson’s Disease is a serious unmet medical need and, for reasons we don’t fully understand, its prevalence is increasing. There’s always more outstanding research to fund than there is money to fund it. The GDNF approach represents one ‘class’ of potential therapies for Parkinson’s Disease and has the potential to address issues that are even broader than this specific therapy alone.”

The Board also approved funding for two clinical trials targeting retinitis pigmentosa (RP), a blinding eye disease that affects approximately 150,000 individuals in the US and 1.5 million people around the world. It is caused by the destruction of light-sensing cells in the back of the eye known as photoreceptors.  This leads to gradual vision loss and eventually blindness.  There are currently no effective treatments for RP.

Dr. Henry Klassen and his team at jCyte are injecting human retinal progenitor cells (hRPCs), into the vitreous cavity, a gel-filled space located in between the front and back part of the eye. The proposed mechanism of action is that hRPCs secrete neurotrophic factors that preserve, protect and even reactivate the photoreceptors, reversing the course of the disease.

CIRM has supported early development of Dr. Klassen’s approach as well as preclinical studies and two previous clinical trials.  The US Food and Drug Administration (FDA) has granted jCyte Regenerative Medicine Advanced Therapy (RMAT) designation based on the early clinical data for this severe unmet medical need, thus making the program eligible for expedited review and approval.

The other project targeting RP is led by Dr. Clive Svendsen from the Cedars-Sinai Regenerative Medicine Institute. In this approach, human neural progenitor cells (hNPCs) are transplanted to the back of the eye of RP patients. The goal is that the transplanted hNPCs will integrate and create a protective layer of cells that prevent destruction of the adjacent photoreceptors. 

The third trial focused on vision destroying diseases is led by Dr. Sophie Deng at the University of California Los Angeles (UCLA). Dr. Deng’s clinical trial addresses blinding corneal disease by targeting limbal stem cell deficiency (LSCD). Under healthy conditions, limbal stem cells (LSCs) continuously regenerate the cornea, the clear front surface of the eye that refracts light entering the eye and is responsible for the majority of the optical power. Without adequate limbal cells , inflammation, scarring, eye pain, loss of corneal clarity and gradual vision loss can occur. Dr. Deng’s team will expand the patient’s own remaining LSCs for transplantation and will use  novel diagnostic methods to assess the severity of LSCD and patient responses to treatment. This clinical trial builds upon previous CIRM-funded work, which includes early translational and late stage preclinical projects.

“CIRM funds and accelerates promising early stage research, through development and to clinical trials,” says Maria T. Millan, MD, President and CEO of CIRM. “Programs, such as those funded today, that were novel stem cell or gene therapy approaches addressing a small number of patients, often have difficulty attracting early investment and funding. CIRM’s role is to de-risk these novel regenerative medicine approaches that are based on rigorous science and have the potential to address unmet medical needs. By de-risking programs, CIRM has enabled our portfolio programs to gain significant downstream industry funding and partnership.”

CIRM Board also awarded $5.53 million to Dr. Rosa Bacchetta at Stanford to complete work necessary to conduct a clinical trial for IPEX syndrome, a rare disease caused by mutations in the FOXP3 gene. Immune cells called regulatory T Cells normally function to protect tissues from damage but in patients with IPEX syndrome, lack of functional Tregs render the body’s own tissues and organs to autoimmune attack that could be fatal in early childhood.  Current treatment options include a bone marrow transplant which is limited by available donors and graft versus host disease and immune suppressive drugs that are only partially effective. Dr. Rosa Bacchetta and her team at Stanford will use gene therapy to insert a normal version of the FOXP3 gene into the patient’s own T Cells to restore the normal function of regulatory T Cells.

The CIRM Board also approved investing $15.80 million in four awards in the Translational Research program. The goal of this program is to help promising projects complete the testing needed to begin talking to the US Food and Drug Administration (FDA) about holding a clinical trial.

The TRAN1 Awards are summarized in the table below:

ApplicationTitleInstitutionAward Amount
TRAN1 11536Ex Vivo Gene Editing of Human Hematopoietic Stem Cells for the Treatment of X-Linked Hyper IgM Syndrome  UCLA $4,896,628
TRAN1 11555BCMA/CS1 Bispecific CAR-T Cell Therapy to Prevent Antigen Escape in Multiple Myeloma  UCLA $3,176,805
TRAN1 11544 Neural Stem cell-mediated oncolytic immunotherapy for ovarian cancer  City of Hope $2,873,262
TRAN1 11611Development of a human stem cell-derived inhibitory neuron therapeutic for the treatment of chronic focal epilepsyNeurona Therapeutics$4,848,750

Newly discovered “don’t eat me” signal shows potential for ovarian and triple-negative breast cancer treatment

Stanford researchers have found that cancer cells have a protein called CD24 on their surface that enables them to protect themselves against the body’s immune cells.
Courtesy of Shutterstock

Getting a breast cancer diagnosis is devastating news in and of itself. Currently, there are treatment options that target three different types of receptors, which are named hormone epidermal growth factor receptor 2 (HER-2), estrogen receptors (ER), and progesterone receptors (PR), commonly found in breast cancer cells, . Unfortunately, in triple-negative breast cancer, which occurs in 10-20% of breast cancer cases, all three receptors are absent, making this form of breast cancer very aggressive and difficult to treat.

In recent years, researchers have discovered that proteins on the cell surface can tell macrophages, an immune cell designed to detect and engulf foreign or abnormal cells, not to eat and destroy them. This can be useful to help normal cells keep the immune system from attacking them, but cancer cells can also use these “don’t eat me” signals to hide from the immune system. 

An illustration of a macrophage, a vital part of the immune system, engulfing and destroying a cancer cell. Antibody 5F9 blocks a “don’t eat me” signal emitted from cancer cells. Courtesy of Forty Seven, Inc.

In fact, because of this concept, a CIRM-funded clinical trial is being conducted that uses an antibody called 5F9 to block a “don’t eat me” signal known as CD47 that is found in cancer cells. The results of this trial, which have been announced in a previous blog post, are very promising.

Further building on this concept, a CIRM-funded study has now discovered a potential new target for triple-negative breast cancer as well as ovarian cancer. Dr. Irv Weissman and a team of researchers at Stanford University have discovered an additional “don’t eat me” signal called CD24 that cancers seem to use to evade detection and destruction by the immune system.

In a press release, Dr. Weissman talks about his work with CD47 and states that,

“Finding that not all patients responded to anti-CD47 antibodies helped fuel our research at Stanford to test whether non-responder cells and patients might have alternative ‘don’t eat me’ signals.” 

The scientists began by looking for signals that were produced more highly in cancers than in the tissues from which the cancers arose. It is here that they discovered CD24 and then proceeded to implant human breast cancer cells in mice for testing. When the CD24 signaling was blocked, the mice’s immune system attacked the cancer cells.

An important discovery was that ovarian and triple-negative breast cancer were highly affected by blocking of CD24 signaling. The other interesting discovery was that the effectiveness of CD24 blockage seems to be complementary to CD47 blockage. In other words, some cancers, like blood cancers, seem to be highly susceptible to blocking CD47, but not to CD24 blockage. For other cancers, like ovarian cancer, the opposite is true. This could suggest that most cancers will be susceptible to the immune system by blocking the CD24 or CD47 signal, and that cancers may be even more vulnerable when more than one “don’t eat me” signal is blocked.

Dr. Weissman and his team are now hopeful that potential therapies to block CD24 signaling will follow in the footsteps of the clinical trials related to CD47.

The full results to the study were published in Nature.

Stem cell stories that caught our eye: better ovarian cancer drugs, creating inner ear tissue, small fish big splash

Two drugs are better than one for ovarian cancer (Karen Ring). Earlier this week, scientists from UCLA reported that a combination drug therapy could be an effective treatment for 50% of aggressive ovarian cancers. The study was published in the journal Precision Oncology and was led by Dr. Sanaz Memarzadeh.

Women with high-grade ovarian tumors have an 85% chance of tumor recurrence after treatment with a common chemotherapy drug called carboplatin. The UCLA team found in a previous study that ovarian cancer stem cells are to blame because they are resistant to carboplatin. It’s because these stem cells have an abundance of proteins called cIAPs, which prevent cell death from chemotherapy.

Ovarian+cancer+tumor+cells_mid

Ovarian cancer cells (blue) expressing cIAP protein (red) on the left are more sensitive to a combination therapy than cancer cells that don’t express the protein on the right. (UCLA Broad Stem Cell Research Center/Precision Oncology)

Memarzadeh discovered that an experimental drug called birinapant made some ovarian cancer tumors more sensitive to chemotherapy treatment by breaking down cIAPs. This gave her the idea that combining the two drugs, birinapant and carboplatin, might be a more effective strategy for treating aggressive ovarian tumors.

By treating with the two drugs simultaneously, the scientists improved the survival rate of mice with ovarian cancer. They also tested this combo drug treatment on 23 ovarian cancer cell lines derived from women with highly aggressive tumors. The treatment killed off half of the cell lines indicating that some forms of this cancer are resistant to the combination treatment.

When they measured the levels of cIAPs in the human ovarian cancer cell lines, they found that high levels of the proteins were associated with ovarian tumor cells that responded well to the combination treatment. This is exciting because it means that clinicians can analyze tumor biopsies for cIAP levels to determine whether certain ovarian tumors would respond well to combination therapy.

Memarzadeh shared her plans for future research in a UCLA news release,

“I believe that our research potentially points to a new treatment option. In the near future, I hope to initiate a phase 1/2 clinical trial for women with ovarian cancer tumors predicted to benefit from this combination therapy.”

In a first, researchers create inner ear tissue. From heart muscle to brain cells to insulin-producing cells, researchers have figured out how to make a long list of different human cell types using induced pluripotent stem cells (iPSCs) – cells taken from the body and reprogrammed into a stem cell-like state.

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Human inner ear organoid with sensory hair cells (cyan) and sensory neurons (yellow). An antibody for the protein CTBP2 reveals cell nuclei as well as synapses between hair cells and neurons (magenta). | Photo: Karl Koehler

This week, a research group at the Indiana University School of Medicine successfully added inner ear cells to that list. This feat, published in Nature Biotechnology, is especially important given the fact that the inner ear is one of the few parts of the body that cannot be biopsied for further examination. With these cells in hands, new insights into the causes of hearing loss and balance disorders may be on the horizon.

The inner ear contains 75,000 sensory hair cells that convert sound waves into electrical signals to the brain. Loud noises, drug toxicity, and genetic mutations can permanently damage the hair cells leading to hearing loss and dizziness. Over 15%  of the U.S. population have some form of hearing loss and that number swells to 67% for people over 75.

Due to the complex shape of the inner ear, the team grew the iPSCs into three dimensional balls of cells rather than growing them as a flat layer of cells on a petri dish. With educated guesses sprinkled in with some trial and error, the scientists, for the time, identified a recipe of proteins that stimulated the iPSCs to transform into inner ear tissue. And like any great recipe, it wasn’t so much the ingredient list but the timing that was key:

“If you apply these signals at the wrong time you can potentially generate a brain instead of an inner ear,” first author Dr. Karl Koehler said in an interview with Gizmodo. “The real breakthrough is that we figured out the exact timing to do each one of these [protein] treatments.”

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Senior author, Eri Hashino, Ph.D., and first author, Karl R. Koehler, Ph.D. Photo: Indiana University

Careful examination shows that the tissue, referred to as organoids, not only contained the sensory hair cells of the inner ear cell but also nerve cells, or neurons, that are responsible for relaying the sound waves to the brain. Koehler explained the importance of this result in a press release:

“We also found neurons, like those that transmit signals from the ear to the brain, forming connections with sensory cells. This is an exciting feature of these organoids because both cell types are critical for proper hearing and balance.”

Though it’s still early days, these iPSC-derived inner ear organoids are a key step toward the ultimate goal of repairing hearing loss. Senior author, Dr. Eri Hashino, talked about the team’s approach to reach that goal:

“Up until now, potential drugs or therapies have been tested on animal cells, which often behave differently from human cells. We hope to discover new drugs capable of helping regenerate the sound-sending hair cells in the inner ear of those who have severe hearing problems.”

This man’s research is no fish tale
And finally, we leave you this week with a cool article and video by STAT. It features Dr. Leonard Zon of Harvard University and his many, many tanks full of zebrafish. This little fish has made a huge splash in understanding human development and disease. But don’t take my word for it, watch the video!