Researchers create a better way to grow blood stem cells

UCLA’s Dr. Hanna Mikkola and Vincenzo Calvanese, lead scientists on the study. Photo courtesy UCLA

Blood stem cells are a vital part of us. They create all the other kinds of blood cells in our body and are used in bone marrow transplants to help people battling leukemia or other blood cancers. The problem is growing these blood stem cells outside the body has always proved challenging. Up till now.

Researchers at UCLA, with CIRM funding, have identified a protein that seems to play a key role in helping blood stem cells renew themselves in the lab. Why is this important? Because being able to create a big supply of these cells could help researchers develop new approaches to treating a wide array of life-threatening diseases.

One of the most important elements that a stem cell has is its ability to self-renew itself over long periods of time. The problem with blood stem cells has been that when they are removed from the body they quickly lose their ability to self-renew and die off.

To discover why this is the case the team at the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA analyzed blood stem cells to see which genes turn on and off as those cells turn into other kinds of blood cells – red, white and platelets. They identified one gene, called MLLT3, which seemed to play a key role in helping blood stem cells self-renew.

To test this finding, the researchers took blood stem cells and, in the lab, inserted copies of the MLLT3 gene into them. The modified cells were then able to self-renew at least 12 times; a number far greater than in the past.

Dr. Hanna Mikkola, a senior author of the study says this finding could help advance the field:

“If we think about the amount of blood stem cells needed to treat a patient, that’s a significant number. But we’re not just focusing on quantity; we also need to ensure that the lab-created blood stem cells can continue to function properly by making all blood cell types when transplanted.”

Happily, that seemed to be the case. When they subjected the MLLT3-enhanced blood stem cells to further analysis they found that they appeared to self-renew at a safe rate and didn’t multiply too much or mutate in ways that could lead to leukemia or other blood cancers.

The next steps are to find more efficient and effective ways of keeping the MLLT3 gene active in blood stem cells, so they can develop ways of using this finding in a clinical setting with patients.

Their findings are published in the journal Nature.

CIRM Board Awards $15.8 Million to Four Translational Research Projects

Last week, the CIRM Board approved $32.92 million in awards directed towards four new clinical trials in vision related diseases and Parkinson’s Disease.

In addition to these awards, the 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.

Before we go into more specific details of each one of these awards, here is a table summarizing these four new projects:

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
Dr. Caroline Kuo, UCLA

$4.89 million was awarded to Dr. Caroline Kuo at UCLA to pursue a gene therapy approach for X-Linked Hyper IgM Syndrome (X-HIM).

X-HIM is a hereditary immune disorder observed predominantly in males in which there are abnormal levels of different types of antibodies in the body.  Antibodies are also known as Immunoglobulin (Ig) and they combat infections by attaching to germs and other foreign substances, marking them for destruction.  In infants with X-HIM, there are normal or high levels of antibody IgM but low levels of antibodies IgG, IgA, and IgE.  The low level of these antibodies make it difficult to fight off infection, resulting in frequent pneumonia, sinus infections, ear infections, and parasitic infections.  Additionally, these infants have an increased risk of cancerous growths. 

The gene therapy approach Dr. Kuo is continuing to develop involves using CRISPR/Cas9 technology to modify human blood stem cells with a functional version of the gene necessary for normal levels of antibody production.  The ultimate goal would be to take a patient’s own blood stem cells, modify them with the corrected gene, and reintroduce them back into the patient.

CIRM has previously funded Dr. Kuo’s earlier work related to developing this gene therapy approach for XHIM.

Dr. Yvonne Chen, UCLA

$3.17 million was awarded to Dr. Yvonne Chen at UCLA to develop a CAR-T cell therapy for multiple myeloma (MM).

MM is a type of blood cancer that forms in the plasma cell, a type of white blood cell that is found in the bone marrow.  An estimated 32,110 people in the United States will be diagnosed with MM in 2019 alone.  Several treatment options are available to patients with MM, but there is no curative therapy.

The therapy that Dr. Chen is developing will consist of a genetically-modified version of the patient’s own T cells, which are an immune system cell that can destroy foreign or abnormal cells.  The T cells will be modified with a protein called a chimeric antigen receptor (CAR) that will recognize BCMA and CS1, two different markers found on the surface of MM cells.  These modified T cells (CAR-T cells) are then infused into the patient, where they are expected to detect and destroy BCMA and CS1 expressing MM cells.

Dr. Chen is using CAR-T cells that can detect two different markers in a separate clinical trial that you can read about in a previous blog post.

Dr. Karen Aboody, City of Hope

$2.87 million was awarded to Dr. Karen Aboody at City of Hope to develop an immunotherapy delivered via neural stem cells (NSCs) for treatment of ovarian cancer.

Ovarian cancer affects approximately 22,000 women per year in the United States alone.  Most ovarian cancer patients eventually develop resistance to chemotherapy, leading to cancer progression and death, highlighting the need for treatment of recurring ovarian cancer.

The therapy that Dr. Aboody is developing will use an established line of NSCs to deliver a virus that specifically targets these tumor cells.  Once the virus has entered the tumor cell, it will continuously replicate until the cell is destroyed.  The additional copies of the virus will then go on to target neighboring tumor cells.  This process could potentially stimulate the body’s own immune response to fight off the cancer cells as well.

Dr. Cory Nicholas, Neurona Therapeutics

$4.85 million was awarded to Dr. Cory Nicholas at Neurona Therapeutics to develop a treatment for epilepsy.

Epilepsy affects more than 3 million people in the United States with about 150,000 newly diagnosed cases in the US every year. It results in persistent, difficult to manage, or uncontrollable seizures that can be disabling and significantly impair quality of life. Unfortunately, anti-epileptic drugs fail to manage the disease in a large portion of people with epilepsy. Approximately one-third of epilepsy patients are considered to be drug-resistant, meaning that they do not adequately respond to at least two anti-epileptic drugs.

The therapy that Dr. Nicholas is developing will derive interneurons from human embryonic stem cells (hESCs). These newly derived interneurons would then be delivered to the brain via injection whereby the new cells are able to help regulate aberrant brain activity and potentially eliminate or significantly reduce the occurrence of seizures.

CIRM has previously funded the early stage development of this approach via a comprehensive grant and discovery grant.

How early CIRM support helped an anti-cancer therapy overcome obstacles and help patients

Dr. Catriona Jamieson, UC San Diego

When you read about a new drug or therapy being approved to help patients it always seems so simple. Researchers come up with a brilliant idea, test it to make sure it is safe and works, and then get approval from the US Food and Drug Administration (FDA) to sell it to people who need it.

But it’s not always that simple, or straight forward. Sometimes it can take years, with several detours along the way, before the therapy finds its way to patients.

That’s the case with a blood cancer drug called fedratinib (we blogged about it here) and the relentless efforts by U.C. San Diego researcher Dr. Catriona Jamieson to help make it available to patients. CIRM funded the critical early stage research to help show this approach could help save lives. But it took many more years, and several setbacks, before Dr. Jamieson finally succeeded in getting approval from the FDA.

The story behind that therapy, and Dr. Jamieson’s fight, is told in the San Diego Union Tribune. Reporter Brad Fikes has been following the therapy for years and in the story he explains why he found it so fascinating, and why this was a therapy that almost didn’t make it.

USC study shows how tumor cells in the bloodstream can target distant organs

Various types of cancer can become particularly aggressive and difficult to treat once they spread from their initial point of origin to other parts of the body. This unfortunate phenomenon, known as metastasis, can make treatment very challenging, decreasing the chance of survival for the patient.

In order to better understand this process, a CIRM supported study at USC looked at breast cancer cells circulating in the blood that eventually invade the brain. The findings, which appear in Cancer Discovery, shed light on how tumor cells in the blood are able to target a particular organ, which may enable the development of treatments than can prevent metastasis from occurring.

Dr. Min Yu

Dr. Min Yu and her lab at USC were able to isolate breast cancer cells from the blood of breast cancer patients whose cancer had already metastasized. The team then expanded the number of cancer cells through a process known as cell culture. These expanded human tumor cells were then injected into the bloodstream of animal models. It was found that these cells migrated to the brain as was predicted.

Upon further analysis, Dr. Yu and her lab discovered a protein on the surface of the tumor cells in the bloodstream that enable them to breach the blood brain barrier, a protective layer around the brain that blocks the passage of certain substances, and enter the brain. Additionally, Dr. Yu and her team discovered another protein inside the tumor cells that shield them from the brain’s immune response, enabling these cells to grow inside the brain.

In a news release in Science Magazine, Dr. Yu talks about how these findings could be used to improve treatment and prevention options for those with aggressive cancers:

“We can imagine someday using the information carried by circulating tumor cells to improve the detection, monitoring and treatment of the spreading cancers. A future therapeutic goal is to develop drugs that get rid of circulating tumor cells or target those molecular signatures to prevent the spread of cancer.”

CIRM has also funded a separate clinical trial related to the treatment of breast cancer related brain metastases.

UCLA Conducts CAR-T Cell Clinical Trial for Patients with Recurring and Non-Responsive Cancers

Dr. Sarah Larson (left) and Dr. Yvonne Chen (right)

There have been many advances made towards the treatment of various cancers, such as deadly forms of leukemia and lymphoma, that were once considered a death sentence and thought to be incurable. Unfortunately, there are still people who do not respond to treatment or eventually relapse and see the cancer return. However, researchers at UCLA are attempting to fine-tune some of these approaches to help people with these recurring and non-treatment responding cancers.

Diagram describing CAR-T cell therapy

Dr. Sarah Larson and Dr. Yvonne Chen at UCLA are conducting a clinical trial that involves genetically-modifying a patient’s own T cells, which are an immune system cell that can destroy foreign or abnormal cells. The T-cells are modified with a protein called a chimeric antigen receptor (CAR), which identifies and destroys the cancer by detecting a specific protein, referred to as an antigen, on the cancer cells. These genetically modified T-cells are referred to as CAR-T cells and are re-introduced back into the patient as part of the therapy.

Previous CAR-T cells developed can only recognize one specific protein. For example, one FDA-approved CAR-T cell therapy is able to recognize a protein called CD19, which is found in B-cell lymphoma and leukemia. However, over time, the cancer cells can lose the CD19 antigen, making the CAR-T cell ineffective and can result in a reoccurrence of the cancer.

In a news release by UCLA, Dr. Larson describes the limitations of this design:

“One of the reasons CAR T cell therapy can stop working in patients is because the cancer cells escape from therapy by losing the antigen CD19, which is what the CAR T cells are engineered to target.”

But Dr. Larson and Dr. Chen are using a CAR-T cell that is able to recognize not one by two proteins simultaneously. In addition to recognizing CD19, their CAR-T cell is also able to recognize a protein called CD20, which is also found in B-cell lymphoma and leukemia. This is called a bispecific CAR-T cell because of it’s ability to identify two protein targets simultaneously.

In the same UCLA news release, Dr. Larson hopes that this approach will be more effective:

“One way to keep the CAR T cells working is to have more than one antigen to target. So by using both CD19 and CD20, the thought is that it will be more effective and prevent the loss of the antigen, which is known as antigen escape, one of the common mechanisms of resistance.”

Before the clinical trial, Dr. Chen and her team at UCLA conducted preclinical studies that showed how using bispecific CAR-T cells provided a much better defense compared to single target CAR-T cells against tumors in mice.

In the same UCLA news release, Dr. Chen elaborate on the results of her preclinical studies:

“Based on these results, we’re quite optimistic that the bispecific CAR can achieve therapeutic improvement over the single-input CD19 CAR that’s currently available.”

This first-in-humans study will evaluate the therapy in patients with non-Hodgkin’s B-cell lymphoma or chronic lymphocytic leukemia that has come back or has not responded to treatment. The goal is to determine a safe therapeutic dose.

CIRM funded research could lead to treatment to prevent recurrence of deadly blood cancer

Chronic myelogenous leukemia

Chronic myelogenous leukemia (CML) is a cancer of the white blood cells. It causes them to increase in number, crowd out other blood cells, leading to anemia, infection or heavy bleeding. Up until the early 2000’s the main weapon against CML was chemotherapy, but the introduction of drugs called tyrosine kinase inhibitors changed that, dramatically improving long term survival rates.

However, these medications are not a cure and do not completely eradicate the leukemia stem cells that can fuel the growth of the cancer, so if people stop taking the medication the cancer can return.

Dr. John Chute: Photo courtesy UCLA

But now Dr. John Chute and a team of researchers at UCLA, in a CIRM-supported study, have found a way to target those leukemia stem cells and possibly eliminate them altogether.

The team knew that mice that had the genetic mutation responsible for around 95 percent of CML cases normally developed the disease and died with a few months. However, mice that had the CML gene but lacked another gene, one that produced a protein called pleiotrophin, had normal white blood cells and lived almost twice as long. Clearly there was something about pleiotrophin that played a key role in the growth of CML.

They tested this by transplanting blood stem cells from mice with the CML gene into healthy mice. The previously healthy mice developed leukemia and died. But when they did the same thing from mice that had the CML gene but lacked the pleiotrophin gene, the mice remained healthy.

So, Chute and his team wanted to know if the same thing happens in human cells. Studying human CML stem cells they found these had not just 100 times more pleiotrophin than ordinary cells, they were also producing their own pleiotrophin.

In a news release Chute, said this was unexpected:

“This provides an example of cancer stem cells that are perpetuating their own disease growth by hijacking a protein that normally supports the growth of the healthy blood system.”

Next Chute and the team developed an antibody that blocked the action of pleiotrophin and when they tested it in human cells the CML stem cells died.

Then they combined this antibody with a drug called imatinib (better known by its brand name, Gleevec) which targets the genetic abnormality that causes most forms of CML. They tested this in mice who had been transplanted with human CML stem cells and the cells died.

“Our results suggest that it may be possible to eradicate CML stem cells by combining this new targeted therapy with a tyrosine kinase inhibitor,” said Chute. “This could lead to a day down the road when people with CML may not need to take a tyrosine kinase inhibitor for the rest of their lives.”

The next step is for the researchers to modify the antibody so that it is better suited for humans and not mice and to see if it is effective not just in cells in the laboratory, but in people.

The study is published in the Journal of Clinical Investigation

Predicting the Impact of Stem Cell Cures on Healthcare Burden in California

A new independent report says developing stem cell treatments and cures for some of the most common and deadly diseases could produce multi-billion dollar benefits for California in reduced healthcare costs and improved quality and quantity of life.

The report, by researchers at the University of Southern California’s Leonard D. Schaeffer Center for Health Policy & Economics, looked at the value of hypothetical future interventions to reduce or cure cancer, diabetes, stroke and blindness.

Predicting the future is always complicated and uncertain and many groups are looking at the best models to determine the value and economic impact of cell and gene therapy as the first products are just entering the market. This study provides some insights into the potential financial benefits of developing effective stem cell treatments for some of the most intractable diseases affecting California today.

The impact could affect millions of people. In 2018 for Californians over the age of 50:

  • Nearly half were predicted to develop diabetes in their lifetime
  • More than one third will experience a stroke
  • Between 5 and 8 percent will develop either breast, colorectal, lung, or prostate cancer

The report says that a therapy that decreased the incidence of diabetes by 50 percent in Californians over the age of 51 would translate into a gain for the state of $322 billion in social value between now and 2050. Even just reducing diabetes 10% would lead to a gain of $60 billion in social value over the same period.

  • For stroke a 50 percent reduction would generate an estimated $229 billion in social value. A 10 percent reduction would generate $47 billion
  • For breast cancer a 50 percent reduction would generate $56 billion in social value; for colorectal cancer it would be $72 billion; for lung cancer $151 billion; and prostate cancer $53 billion. 

The impact of a cure for any one of those diseases would be enormous. For example, a 51-year-old woman cured of lung cancer could expect to gain a lifetime social value of almost half a million dollars ($467,275). That’s a measure of years of healthy life gained, of years spent enjoying time with family and friends and not wasting away or lying in a hospital bed.

The researchers say: “Though advances in scientific research defy easy predictions, investing in biomedical research is important if we want to reduce the burden of common and costly diseases for individuals, their families, and society. These findings show the value and impact breakthrough treatments could have for California.”

“Put in this context, the CIRM investment would be worthwhile if it increased our chances of success even modestly. Against the billions of dollars in disease burden facing California, the relatively small initial investment is already paying dividends as researchers work to bring new therapies to patients.”

The researchers determined the “social value” using a measure called a quality adjusted life-year (QALY). This is a way of estimating the cost effectiveness and consequences of treating or not treating a disease. For example, one QALY is equivalent to one year of perfect health for an individual. In this study the value of that year was estimated at $150,000. If someone is sick with, say, diabetes, their health would be estimated to be 0.5 QALY or $75,000. So, the better health a person enjoys and the longer they enjoy it the higher QALY score they accumulate. In the case of a disease affecting millions of people in that state or country that can obviously lead to very large QALY scores representing potentially billions of dollars.

New Report Says CIRM Produces Big Economic Boost for California

An independent Economic Impact Report says the California Institute for Regenerative Medicine (CIRM) has had a major impact on California’s economy, creating tens of thousands of new jobs, generating hundreds of millions of dollars in new taxes, and producing billions of dollars in additional revenue for the state.

The report, done by Dan Wei and Adam Rose at the Price School of Public Policy at the University of Southern California, looked at the impacts of CIRM funding on both the state and national economy from the start of the Stem Cell Agency in 2004 to the end of 2018.

The total impacts on the California economy are estimated to be:

  • $10.7 billion of additional gross output (sales revenue)
  • $641.3 million of additional state/local tax revenues
  • $726.6 million of additional federal tax revenues
  • 56,549 additional full-time equivalent (FTE) jobs, half of which offer salaries considerably higher than the state average

Maria Millan, M.D., CIRM’s President and CEO, says the report reflects the Agency’s role in building an ecosystem to accelerate the translation of important stem cell science to solutions for patients with unmet medical needs. “CIRM’s mission on behalf of patients has been the priority from day one, but this report shows that CIRM funding brings additional benefits to the state. This report reflects how CIRM is promoting economic growth in California by attracting scientific talent and additional capital, and by creating an environment that supports the development of businesses and commercial enterprises in the state”

In addition to the benefits to California, the impacts outside of California on the US economy are estimated to be:

  • $4.7 billion of additional gross output (sales revenue)
  • $198.7 million of additional state (non-Californian) & local tax revenue
  • $208.6 million of additional federal tax revenues
  • 25,816 additional full-time equivalent (FTE) jobs

The researchers summarize their findings, saying: “In terms of economic impacts, the state’s investment in CIRM has paid handsome dividends in terms of output, employment, and tax revenues for California.”

The estimates in the report are based on the economic stimulus created by CIRM funding and by the co-funding that researchers and companies were required to provide for clinical and late-stage preclinical projects. The estimates also include:

  • Investments in CIRM-supported projects from private funders such as equity investments, public offerings and mergers and acquisitions,
  • Follow-on funding from the National Institutes of Health and other organizations due to data generated in CIRM-funded projects
  • Funding generated by clinical trials held at CIRM’s Alpha Stem Cell Clinics network

The researchers state “Nearly half of these impacts emanate from the $2.67 billion CIRM grants themselves.”

“The economic impact of California’s investment in stem and regenerative cell research is reflective of significant progress in this field that was just being born at the time of CIRM’s creation,” says Dr. Millan. “We fund the most promising projects based on rigorous science from basic research into clinical trials. We partnered with researchers and companies to increase the likelihood of success and created specialized infrastructure such as the Alpha Clinics Network to support the highest quality of clinical care and research standards for these novel approaches.  The ecosystem created by CIRM has attracted scientists, companies and capital from outside the state to California. By supporting promising science projects early on, long before most investors were ready to come aboard, we enabled our scientists to make progress that positioned them to attract significant commercial investments into their programs and into California.”

These partnerships have helped move promising therapies out of the lab and into clinical trials for companies like Orchard Therapeutics’ successful treatment for Severe Combined Immunodeficiency and Forty Seven Inc.’s innovative approach to treating cancer.

Dr. Don Kohn: Photo courtesy UCLA Jonsson Comprehensive Cancer Center

“I think one of the greatest strengths of CIRM has been their focus on development of new stem cell therapies that can become real medicines,” says UCLA and Orchard Therapeutics’ Don Kohn, M.D. “This has meant guiding academic investigators to do the things that may be second nature in industry/pharmaceutical companies but are not standard for basic or clinical research.  The support from CIRM to perform the studies and regulatory activities needed to navigate therapies through the FDA and to form alliances with biotech and pharma companies has allowed the stem cell gene therapy we developed to treat SCID babies to be advanced and licensed to Orchard Therapeutics who can make it available to patients across the country.”

Dr. Mark Chao: Photo courtesy Forty Seven Inc.

“CIRM’s support has been instrumental to our early successes and our ability to rapidly progress Forty Seven’s CD47 antibody targeting approach with magrolimab,” says Mark Chao, M.D., Ph.D., Founder and Vice President of Clinical Development at Forty Seven Inc. “ CIRM was an early collaborator in our clinical programs, and will continue to be a valued partner as we move forward with our MDS/AML clinical trials.”

The researchers say the money generated by partnerships and investments, what is called “deal-flow funding”, is still growing and that the economic benefits created by them are likely to continue for some time: “Deal-flow funding usually involves several waves or rounds of capital infusion over many years, and thus is it expected that CIRM’s past and current funding will attract increasing amounts of industry investment and lead to additional spending injections into the California economy in the years to come.”

They conclude their report by saying: “CIRM has led to California stem cell research and development activities becoming a leader among the states.”

Engineered T cells made from stem cells could provide immunity against multiple cancers

Dr. Lily Yang

Within all of our bodies there is a special type of “super” immune cell that holds enormous potential. Unlike regular immune cells that can only attack one cancer at a time, these “super” immune cells have the ability to target many types of cancers at once. These specialized cells are known as invariant natural killer T cells or iNKT cells for short. Unfortunately, there are relatively few of these cells normally present in the body.

However, in a CIRM-funded study, Dr. Lily Yang and her team of researchers at UCLA have found a way to produce iNKT cells from human blood stem cells. They were then able to test these iNKT cells on mice with both human bone marrow and human cancers. These mice either had multiple melanoma, a type of blood cancer, or melanoma, a solid tumor cancer. The researchers then studied what happened to mice’s immune system, cancers, and engineered iNKT cells after they had integrated into the bone marrow.

The results were remarkable. The team found that the blood stem cells now differentiated normally into iNKT cells, producing iNKT cells for the rest of the animal’s life, which was generally about a year. Mice without the engineered stem cell transplants had undetectable levels of iNKT cells while those that received the engineered cells had iNKT cells make up as much as 60% of the total immune system cells. The team also found that the engineered iNKT cells were able to suppress tumor growth in both multiple myeloma and melanoma.

Dr. Yang, in a press release by UCLA health, discussed the significance of the results in this animal model and the enormous potential this could have for cancer patients.

“What’s really exciting is that we can give this treatment just once and it increases the number of iNKT cells to levels that can fight cancer for the lifetime of the animals.” said Yang.

In the same press release, Dr. Yang continued to highlight the study’s importance by saying that,

“One advantage of this approach is that it’s a one-time cell therapy that can provide patients with a lifelong supply of iNKT cells.”

Researchers mentioned that they could control total iNKT cell make up in the immune system depending on how they engineered the blood stem cells. However, more research is needed to determine how these engineered iNKT cells might be useful for treating cancer in humans and evaluating any long-term side effects associated with an increased number of these cells.

The full results of this study were published in the journal Cell Stem Cell.

Drug used to treat multiple sclerosis may improve glioblastoma outcomes

Dr. Jeremy Rich, UC San Diego

Glioblastoma is an aggressive form of cancer that invades brain tissue, making it extremely difficult to treat. Current therapies involving radiation and chemotherapy are effective in destroying the bulk of brain cancer cells, but they are not able to reach the brain cancer stem cells, which have the ability to grow and multiply indefinitely. These cancer stem cells enable the glioblastoma to continuously grow even after treatment, which leads to recurring tumor formation.

Dr. Jeremy Rich and his team at UC San Diego examined glioblastomas further by obtaining glioblastoma tumor samples donated by patients that underwent surgery and implanting these into mice. Dr. Rich and his team tested a combinational treatment that included a targeted cancer therapy alongside a drug named teriflunomide, which is used to treatment patients with multiple sclerosis. The research team found that this approach successfully halted the growth of glioblastoma stem cells, shrank the tumor size, and improved survival in the mice.

In order to continue replicating, glioblastoma stem cells make pyrimidine, one of the compounds that make up DNA. Dr. Rich and his team noticed that higher rates of pyrimidine were associated with poor survival rates in glioblastoma patients. Teriflunomide works by blocking an enzyme that is necessary to make pyrmidine, therefore inhibiting glioblastoma stem cell replication.

In a press release, Dr. Rich talks about the potential these findings hold by stating that,

“We’re excited about these results, especially because we’re talking about a drug that’s already known to be safe in humans.”

However, he comments on the need to evaluate this approach further by saying that,

“This laboratory model isn’t perfect — yes it uses human patient samples, yet it still lacks the context a glioblastoma would have in the human body, such as interaction with the immune system, which we know plays an important role in determining tumor growth and survival. Before this drug could become available to patients with glioblastoma, human clinical trials would be necessary to support its safety and efficacy.”

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