Biotechnology companies join forces in developing treatment for X-SCID

Jasper Therapeutics, Inc., a biotechnology company focused on blood stem cell therapies, and Graphite Bio, Inc., a biotechnology company focused on gene editing therapies to treat or cure serious diseases, announced a research and clinical collaboration for a treatment for X-SCID.

X-SCID, which stands for X-linked severe combined immunodeficiency, is a genetic disorder that interferes with the normal development of the immune system, leaving infants vulnerable to infections that most people can easily fight off. One treatment for X-SCID involves a blood stem cell transplant, in which the patient’s defective stem cells are wiped out with chemotherapy or radiation to make room for normal blood stem cells to take their place. Unfortunately, the problem with chemotherapy or radiation in young infants is that it can lead to lifelong effects such as neurological impairment, growth delays, infertility, and risk of cancer.

Fortunately, Jasper Therapeutics has developed JSP191, a non-toxic alternative to chemotherapy and radiation. It is an antibody that works by targeting and removing the defective blood forming stem cells. The approach has previously been used in a CIRM-funded clinical trial ($20M award) for X-SCID.

Graphite Bio has developed GPH201, the first-in-human investigational blood stem cell treatment that will be evaluated as a potential cure for patients suffering from X-SCID. GPH201 is generated using precise and efficient gene editing technology, It works by directly replacing a defective gene that causes problems with the immune system. The hope is that GPH201 will ultimately lead to the production of fully functional, healthy immune cells.

The ultimate goal of this collaboration is to use JSP191 as the non-toxic alternative to chemotherapy in patients in order to remove their defective blood stem cells. After that, the gene editing blood stem cell technology developed by Graphite Bio can be introduced to patients in order to treat X-SCID. The two companies have agreed to collaborate on research, and potentially a clinical study, evaluating JSP191 as the non-toxic conditioning agent for GPH201.

In a press release, Josh Lehrer, M.Phil., M.D., chief executive officer at Graphite Bio, expressed excitement about the collaboration between the two companies.

“This collaboration with Jasper demonstrates our shared commitment to pioneering novel therapeutic approaches with the potential to significantly improve the treatment experiences of individuals with devastating conditions who stand to benefit from gene replacement therapies, initially for patients with XSCID. GPH201 harnesses our targeted gene integration platform to precisely target the defective gene that causes XSCID and replace it with a normal copy.”

In the same press release, Bill Lis, executive chairman and CEO of Jasper Therapeutics, also expressed optimism in regards to the two companies teaming up.

“Our collaboration with Graphite Bio is an exciting opportunity to further advance the field of curative gene correction by combining a targeted gene integration platform with our first-in-class targeted CD117 antibody, JSP191, that has already demonstrated preliminary clinical efficacy and safety as a conditioning agent in X-SCID patients and those with blood cancers undergoing allogeneic hematopoietic stem cell transplant.”

Graphite Bio is also developing gene editing technology to help treat sickle cell disease.  It is currently supported by a CIRM  late stage preclinical grant ($4.8M award). Th goal is to complete the final preclinical studies, which will allow Graphite Bio to start clinical studies of the sickle cell disease gene therapy in sickle cell patients in 2021.

A retrospective look at CIRM and gratitude for continued support

Maria T. Millan, M.D.
President & CEO, CIRM

This whole month we have highlighted CIRM and have taken a look back at what has been accomplished since the organization was created in 2004.  We end our month of CIRM with a letter from our President & CEO Maria T. Millan, M.D.

As we move onward into 2021, I can’t help but reflect on the magnitude of CIRM’s reach and impact since its inception and the tremendous opportunities we have going forward!

Just look at the 68 clinical trials funded to date by CIRM; an amalgam that is representative of the numerous approaches in precision medicine for various disease areas. As highlighted in the sickle cell disease webinar with CIRM’s Senior Science Officer Ingrid Caras, Ph.D, we took a tour of CIRM’s clinical trials and heard from Evie Junior, a sickle cell disease patient who described his inclusion in the trial as a lifechanging experience that gives him hope for a better future.  The convergence of committed researchers and tremendous scientific advancements in California brings us closer to a cure for sickle cell. The CIRM funded work of Dr. Mark Walters’ at UCSF and Dr. Matt Porteus’ of Stanford each utilize the powerful CRISPR-Cas9 gene editing technology of California’s recent Nobel laureate Dr. Jennifer Doudna in different ways to correct the underlying mutation in Sickle Cell Disease. Each of these curative intent therapies have received FDA clearance to advance to clinical testing. 

In my recent  interview with Moderna’s co-founder Dr. Derrick Rossi, we heard about how Dr. Rossi, initially trained as a molecular biologist, pursued his post-doctoral training in stem cell research at Stanford in the lab of Dr. Weissman. He was funded by one of CIRM’s education grants and was in the first crop of “CIRM Scholars.” He then went on to develop the novel mRNA technology in his own stem cell lab at Harvard, the same mRNA technology that was spun out and further developed by the company, Moderna. When COVID-19 hit and the viral sequence was published, Moderna was able to rapidly deploy this revolutionary mRNA technology and, within 11 months, delivered a rigorously tested, FDA approved, highly efficacious vaccine.  Dr. Rossi’s story certainly highlights the value of investments in educating and training the scientists and workforce of tomorrow in the evolving field of stem cell science and regenerative medicine.

This past November, Californians reaffirmed their commitment to CIRM by approving Proposition 14 and an additional $5.5 billion investment. With deep gratitude for the opportunity to continue our mission to advance science and regenerative medicine treatments to patients in need, we wasted no time in re-opening funding opportunities to support discovery stage, translational and clinical research. Additional programs are underway as we build up our team, upgrade operations and develop our Strategic Plan. We have already “hardwired” provisions into our research programs that empower our researchers to incorporate considerations of diversity, equity and inclusion. There is more work to be done and we are up to that challenge. I am so proud of the CIRM team including the Review team, Therapeutics team, Discovery & Translation team, Grants Management, Finance, Administration, Communications, Business Development, and Legal. This team never slowed down even when we did not know what the outcome of Proposition 14 would be. When the votes came in and Proposition 14 passed, the Team suited up and headed for the launch pad!

We remain fully committed to accelerating scientific advancements and treatments to patients in need. We also respect that good medicine is born from good science and good science takes time and patience. As a philosopher once said, “Patience is bitter, but its fruit is sweet.”  CIRM is in the position to leverage the successes and lessons learned from its Prop 71 days of 2004-2020. With the formal passage of Prop 14 in December 2020, CIRM will now leverage its “value proposition” and the collective intellectual capital of its robust ecosystem to chart new paths forward in partnership with the broader community!

DNA therapeutic treats blood cancer in mice and begins human clinical trial

The left image represents a microscopic view of the bone marrow of a myeloma-bearing mouse treated with control, and the right image represents the same for a myeloma-bearing mouse treated with ION251, an experimental therapeutic. The red dots represent the IRF4 protein within human myeloma cells, which are much sparser after ION251 treatment. Image credit: UC San Diego Health

Multiple myeloma is the second most common blood cancer in the United States, with more than 32,000 new cases predicted in 2020.  Unfortunately, many patients with this type of blood cancer eventually develop resistance to multiple types of treatments.  This phenomenon is partially due to the fact that cancer stem cells, which have the ability to evade traditional therapies and then self-renew, help drive the disease.

It is for this reason that a team of researchers, at the UC San Diego School of Medicine and Ionis Pharmaceuticals, are developing a therapy that can destroy these malignant stem cells, thereby preventing the cancer from coming back.  With support from CIRM, the team developed an approach that interacts with IRF4, a gene that allows myeloma stem cells and tumor cells to grow and survive chemotherapy and radiation.  They have engineered an oligonucleotide, a short DNA molecule, to prevent IRF4 from functioning.  The therapy, known as ION251, lowered disease burden, reduced the amount of myeloma stem cells, and increased survival when tested in mice bearing human myeloma.  These results have enabled the team to start a Phase I clinical trial to see if this approach is safe and effective in people with myeloma.

To study the disease and test ION251, the team transplanted human myeloma cells into mice that lack an immune system and thus won’t reject human cells.  Ten mice received the ION251 treatment and an additional ten mice received a control treatment.  After receiving the ION251 therapy, the treated mice had significantly fewer myeloma cells after two to six weeks of treatment.  Additionally, 70 to 100 percent of the treated mice survived, whereas none of the untreated control mice did. 

In a news release from UC San Diego Health, Dr. Leslie Crews, co-senior author and assistant professor at the UCSD School of Medicine, elaborated on the promising results from the mouse study.

“The results of these preclinical studies were so striking that half the microscopy images we took to compare bone marrow samples between treated and untreated mice kept coming back blank — in the treated mice, we couldn’t find any myeloma cells left for us to study.  It makes the science more difficult, but it gives me hope for patients.”

The Phase I clinical trial to assess the safety of ION251, sponsored by Ionis Pharmaceuticals, is now recruiting participants at Moores Cancer Center at UC San Diego Health and elsewhere. More information on this can be viewed by clicking the link here.

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

CIRM funded researchers discover link between Alzheimer’s gene and COVID-19

Dr. Yanhong Shi (left) and Dr. Vaithilingaraja Arumugaswami (right)

All this month we are using our blog and social media to highlight a new chapter in CIRM’s life, thanks to the voters approving Proposition 14. We are looking back at what we have done since we were created in 2004, and also looking forward to the future. Today we focus on groundbreaking CIRM funded research related to COVID-19 that was recently published.

It’s been almost a year since the world started hearing about SARS-CoV-2, the virus that causes COVID-19.  In our minds, the pandemic has felt like an eternity, but scientists are still discovering new things about how the virus works and if genetics might play a role in the severity of the virus.  One population study found that people who have ApoE4, a gene type that has been found to increase the risk of developing Alzheimer’s, had higher rates of severe COVID-19 and hospitalizations.

It is this interesting observation that led to important findings of a study funded by two CIRM awards ($7.4M grant and $250K grant) and conducted by Dr. Yanhong Shi at City of Hope and co-led by Dr. Vaithilingaraja Arumugaswami, a member of the UCLA Broad Stem Cell Research Center.  The team found that the same gene that increases the risk for Alzheimer’s disease can increase the susceptibility and severity of COVID-19.

At the beginning of the study, the team was interested in the connection between SARS-CoV-2 and its effect on the brain.  Due to the fact that patients typically lose their sense of taste and smell, the team theorized that there was an underlying neurological effect of the virus.  

The team first created neurons and astrocytes.  Neurons are cells that function as the basic working unit of the brain and astrocytes provide support to them.  The neurons and astrocytes were generated from induced pluripotent stem cells (iPSCs), which are a kind of stem cell that can become virtually any type of cell and can be created by “reprogramming” the skin cells of patients.  The newly created neurons and astrocytes were then infected with SARS-CoV-2 and it was found that they were susceptible to infection.

Next, the team used iPSCs to create brain organoids, which are 3D models that mimic certain features of the human brain.  They were able to create two different organoid models: one that contained astrocytes and one without them.  They infected both brain organoid types with the virus and discovered that those with astrocytes boosted SARS-CoV-2 infection in the brain model. 

The team then decided to further study the effects of ApoE4 on susceptibility to SARS-CoV-2.  They did this by generating neurons from iPSCs “reprogrammed” from the cells of an Alzheimer’s patient.  Because the iPSCs were derived from an Alzheimer’s patient, they contained ApoE4.  Using gene editing, the team modified some of the ApoE4 iPSCs created so that they contained ApoE3, which is a gene type considered neutral.  The ApoE3 and ApoE4 iPSCs were then used to generate neurons and astrocytes.

The results were astounding.  The ApoE4 neurons and astrocytes both showed a higher susceptibility to SARS-CoV-2 infection in comparison to the ApoE3 neurons and astrocytes.  Moreover, while the virus caused damage to both ApoE3 and ApoE4 neurons, it appeared to have a slightly more severe effect on ApoE4 neurons and a much more severe effect on ApoE4 astrocytes compared to ApoE3 neurons and astrocytes. 

“Our study provides a causal link between the Alzheimer’s disease risk factor ApoE4 and COVID-19 and explains why some (e.g. ApoE4 carriers) but not all COVID-19 patients exhibit neurological manifestations” says Dr. Shi. “Understanding how risk factors for neurodegenerative diseases impact COVID-19 susceptibility and severity will help us to better cope with COVID-19 and its potential long-term effects in different patient populations.”

In the last part of the study, the researchers tested to see if the antiviral drug remdesivir inhibits virus infection in neurons and astrocytes.  They discovered that the drug was able to successfully reduce the viral level in astrocytes and prevent cell death.  For neurons, it was able to rescue them from steadily losing their function and even dying. 

The team says that the next steps to build on their findings is to continue studying the effects of the virus and better understand the role of ApoE4 in the brains of people who have COVID-19.  Many people that developed COVID-19 have recovered, but long-term neurological effects such as severe headaches are still being seen months after. 

“COVID-19 is a complex disease, and we are beginning to understand the risk factors involved in the manifestation of the severe form of the disease” says Dr. Arumugaswami.  “Our cell-based study provides possible explanation to why individuals with Alzheimer’s’ disease are at increased risk of developing COVID-19.”

The full results to this study were published in Cell Stem Cell.

A look back: CIRM funded trial aims to help patients suffering from chronic viral infections

Dr. Michael Pulsipher

All this month we are using our blog and social media to highlight a new chapter in CIRM’s life, thanks to the voters approving Proposition 14. We are looking back at what we have done since we were created in 2004, and also looking forward to the future. Today we look at a way of making blood stem cell transplants safer and more readily available

Blood stem cell transplants have provided lifechanging treatments to individuals.  This statement is observed firsthand in several patients in CIRM funded trials for X-linked Chronic Granulomatous Disease (X-CGD), Sickle Cell Disease (SCD), and Severe Combined Immunodeficiency (SCID).  The personal journeys of Evangelina Padilla-Vaccaro, Evie Junior, and Brenden Whittaker speak volumes for the potential this treatment holds.  In these trials, defective blood stem cells from the patient are corrected outside the body and then returned to the patient in a transplant procedure.

Unfortunately, there is still a certain degree of risk that accompanies this procedure.  Before a blood stem cell transplant can be performed,  diseased or defective blood stem cells in the patient’s bone marrow need to be removed using chemotherapy or radiation to make room for the transplant.  This leaves the patient temporarily without an immune system and at risk for a life-threatening viral infection.  Additionally, viral infections pose a serious risk to patients with immune deficiency disorders, with viruses accounting upwards of 40% of deaths in these patients.

That’s why in October 2017, the CIRM ICOC Board awarded $4.8M to fund a clinical trial conducted by Dr. Michael Pulsipher at the Children’s Hospital of Los Angeles.  Dr. Pulsipher and his team are using virus-specific T cells (VSTs), a special type of cell that plays an important role in the immune response, to treat immunosuppressed or immune deficient patients battling life-threatening viral infections.  This trial includes patients with persistent viral infections after having received a blood stem cell transplant as well as those with immune deficiency disorders that have not yet received a blood stem cell transplant.  The VSTs used in this trial specifically treat cytomegalovirus (CMV), Epstein-Barr virus (EBV), and adenovirus infections.  They are manufactured using cells from healthy donors and are banked so as to be readily available when needed. 

One challenge of receiving a stem cell transplant can be finding a patient and donor that are a close or identical match.  This is done by looking at specific human leukocyte antigens (HLA), which are protein molecules we inherit from our parents.  To give you an idea of how challenging this can be, you only have a 25% chance of being an HLA identical match with your sibling. 

Because VSTs are temporary soldiers that are administered to fight the viral infection and then disappear, Dr. Pulsipher and his team are using partially HLA-matched VSTs to treat patients in their trial.  Previous studies have indicated that partially HLA-matched T-cells can be effective in treating patients.  The availability of partially HLA-matched VST banks that can be used “off the shelf” improves accessibility and shortens the time for patients to receive VST therapy, which will save lives.

To learn more about Dr. Pulsipher’s work, please view the video below:

Anticipating the Future of Regenerative Medicine: CIRM’s Alpha Stem Cell Clinics Network

All this month we are using our blog and social media to highlight a new chapter in CIRM’s life, thanks to the voters approving Proposition 14. We are looking back at what we have done since we were created in 2004, and also looking forward to the future. Today we take a deeper dive into CIRM’s Alpha Stem Cell Clinics Network.  The following is written by Dr. Geoff Lomax, Senior Officer of CIRM Therapeutics and Strategic Infrastructure.

The year 2014 has been described as the regenerative medicine renaissance: the European Union approved its first stem cell-based therapy and the FDA authorized ViaCyte’s CIRM funded clinical trial for diabetes. A path forward for stem cell treatments had emerged and there was a growing pipeline of products moving towards the clinic. At the time, many in the field came to recognize the need for clinical trial sites with the expertise to manage this growing pipeline. Anticipating this demand, CIRM’s provided funding for a network of medical centers capable of supporting all aspect of regenerative medicine clinical trials. In 2015, the Alpha Stem Cell Clinics Network was launched to for this purpose.

The Alpha Clinics Network is comprised of leading California medical centers with specific expertise in delivering patient-centered stem cell and gene therapy treatments. UC San Diego, City of Hope, UC Irvine and UC Los Angeles were included in the initial launch, and UC San Francisco and UC Davis entered the network in 2017. Between 2015 and 2020 these sites supported 105 regenerative medicine clinical trials. Twenty-three were CIRM-funded clinical trials and the remaining 82 were sponsored by commercial companies or the Alpha Clinic site. These trials are addressing unmet medical needs for almost every disease where regenerative medicine is showing promise including blindness, blood disorders (e.g. sickle cell disease) cancer, diabetes, HIV/AIDS, neurological diseases among others.

As of spring of 2020 the network had inked over $57 million in contracts with commercial sponsors. High demand for Alpha Clinics reflects the valuable human and technical resources they provide clinical trial sponsors. These resources include:

  • Skilled patient navigators to educate patients and their families about stem cell and gene therapy treatments and assist them through the clinical trial process.
  • Teams and facilities specialized in the manufacturing and/or processing of patients’ treatments. In some instances, multiple Alpha Clinic sites collaborate in manufacturing and delivery of a personalized treatment to the patient.
  • Nurses and clinicians with experience with regenerative medicine and research protocols to effectively deliver treatments and subsequently monitor the patients.

The multi- site collaborations are an example of how the network operates synergistically to accelerate the development of new treatments and clinical trials. For example, the UC San Francisco Alpha Clinic is collaborating with UC Berkeley and the UC Los Angeles Alpha Clinic to develop a CIRM-funded gene therapy for sickle cell disease. Each partner brings a unique expertise to the program that aims to correct a genetic mutilation in the patients’ blood stem cells to effectively cure the disease. Most recently, City of Hope has partnered with UC Irvine and UC San Diego as part of CIRM’s COVID-19 research program to study how certain immune system antibodies might be used as a treatment for respiratory disease in infected patients. In another COVID-19 study, UC Irvine and UC Davis are working with a commercial sponsor to evaluate a treatment for infected adults.

The examples above are a small sample of the variety of collaborations CIRM funding has enabled. As the Alpha Clinics track record grown, sponsors are increasingly coming to California to enable the success of their research programs. Sponsors with trials running across the country have noted a desire to expand their number of Alpha Clinic sties because they consistently perform at the highest level.

Back in 2014, it was hard to imagine over one hundred clinical trials would be served by the CIRM network in just five years. Fortunately, CIRM was able to draw on the knowledge of its internal team, external advisors and the ICOC to anticipate this need and provide California infrastructure to rise to the occasion.

“Mini-brains” model an autism spectrum disorder and help test treatments

Alysson Muotri, PhD, professor and director of the Stem Cell Program at UC San Diego School of Medicine
and member of the Sanford Consortium for Regenerative Medicine.
Image credit: UC San Diego Health

Rett syndrome is a rare form of autism spectrum disorder that impairs brain development and causes problems with movement, speech, and even breathing. It is caused by mutations in a gene called MECP2 and primarily affects females. Although there are therapies to alleviate symptoms, there is currently no cure for this genetic disorder.

With CIRM funding ($1.37M and $1.65M awards), Alysson Muotri, PhD and a team of researchers at the University of California San Diego School of Medicine and Sanford Consortium for Regenerative Medicine have used brain organoids that mimic Rett syndrome to identify two drug candidates that returned the “mini-brains” to near-normal. The drugs restored calcium levels, neurotransmitter production, and electrical impulse activity.

Brain organoids, also referred to as “mini-brains”, are 3D models made of cells that can be used to analyze certain features of the human brain. Although they are far from perfect replicas, they can be used to study changes in physical structure or gene expression over time.

Dr. Muotri and his team created induced pluripotent stem cells (iPSCs), a type of stem cell that can become virtually any type of cell. For the purposes of this study, they were created from the skin cells of Rett syndrome patients. The newly created iPSCs were then turned into brain cells and used to create “mini-brains”, thereby preserving each Rett syndrome patient’s genetic background. In addition to this, the team also created “mini-brains” that artificially lack the MECP2 gene, mimicking the issues with the same gene observed in Rett syndrome.

Lack of the MECP2 gene changed many things about the “mini-brains” such as shape, neuron subtypes present, gene expression patterns, neurotransmitter production, and decreases in calcium activity and electrical impulses. These changes led to major defects in the emergence of brainwaves.

To correct the changes caused by the lack of the MECP2 gene, the team treated the brain organoids with 14 different drug candidates known to affect various brain cell functions. Of all the drugs tested, two stood out: nefiracetam and PHA 543613. The two drugs resolved nearly all molecular and cellular symptoms observed in the Rett syndrome “mini-brains”, with the number active neurons doubling post treatment.

The two drugs were previously tested in clinical trials for the treatment of other conditions, meaning they have been shown to be safe for human consumption.

In a news release from UC San Diego Health, Dr. Muotri stresses that although the results for the two drugs are promising, the end treatment for Rett syndrome may require a multi-drug cocktail of sorts.

“There’s a tendency in the neuroscience field to look for highly specific drugs that hit exact targets, and to use a single drug for a complex disease. But we don’t do that for many other complex disorders, where multi-pronged treatments are used. Likewise, here no one target fixed all the problems. We need to start thinking in terms of drug cocktails, as have been successful in treating HIV and cancers.”

The full results of this study were published in EMBO Molecular Medicine.

CIRM-funded study discovers potential therapy for one of the leading causes of heart disease

Dr. Deepak Srivastava and his team found a drug candidate that could help prevent tens of thousands of heart surgeries every year. Image Credit: Gladstones Institute

According to the Center for Disease Control and Prevention (CDC), heart disease is the leading cause of death for men, women, and people of most racial and ethnic groups in the United States. About 655,000 Americans die from heart disease each year, which is about one in every four deaths.

Calcific aortic valve disease, the third leading cause of heart disease overall, occurs when calcium starts to accumulate in the heart valves and vessels over time, causing them to gradually harden like bone. This leads to obstruction of blood flow out of the heart’s pumping chamber, causing heart failure. Unfortunately there is no treatment for this condition, leaving patients only with the option of surgery to replace the heart valve once the hardening is severe enough.

But thanks to a CIRM-funded ($2.4 million) study conducted by Dr. Deepak Srivastava and his team at the Gladstone Institutes, a potential drug candidate for heart valve disease was discovered. It has been found to function in both human cells and animals and is ready to move toward a clinical trial.

For this study, Dr. Srivastava and his team looked for drug-like molecules that had the potential to correct the mechanism in heart valve disease that leads to gradual hardening. To do so, the team first had to determine the network of genes that are turned on or off in the diseased cells.

Once the genes were identified, they used an artificial intelligence method to train a machine learning program to detect whether a cell was healthy or diseased based on the network of genes identified. They proceeded to treat the diseased human cells with nearly 1,600 molecules in order to identify any drugs that would cause the machine learning program to reclassify diseased cells as healthy. The team successfully identified a few molecules that could correct diseased cells back to a healthy state.

Dr. Srivastara then collaborated with Dr. Anna Malashicheva, from the Russian Academy of Sciences, who had collected valve cells from over 20 patients at the time of surgical replacement. Using the valve cells that Dr. Malashicheva had collected, Dr. Srivastara and his team conducted a “clinical trial in a dish” in which they tested the molecules they had previously identified in the cells from the 20 patients with aortic valve hardening. The results were remarkable, as the molecule that seemed most effective in the initial study was able to restore these patients’ cells as well.

The final step taken was to determine whether the drug-like molecule would actually work in a whole, living organ. To do this, Dr. Srivastava and his team did a “pre-clinical trial” in a mouse model of the disease. The team found that the therapeutic candidate could successfully prevent and treat aortic valve disease. In young mice who had not yet developed the disease, the therapy prevented the hardening of the valve. In mice that already had the disease, the therapy was able to halt the disease and, in some cases, reverse it. This finding is especially important since most patients aren’t diagnosed until hardening of the heart valve has already begun.

Dr. Deepak Srivastava (left) and Dr. Christina V. Theodoris (right)
Image Credit: Gladstones Institute

Dr. Christina V. Theodoris, a lead author of the study who is now completing her residency in pediatric genetics, was a graduate student in Dr. Srivastava’s lab and played a critical role in this research. Her first project was to convert the cells from patient families into induced pluripotent stem cells (iPSCs), which have the potential of becoming any cell in the body. The newly created iPSCs were then turned into cells that line the valve, allowing the team to understand why the disease occurs. Her second project was to make a mouse model of calcific aortic valve disease, which enabled them to start using the models to identify a therapy.

In a press release from Gladstone Institutes, Dr. Theodoris, discusses the impact of the team’s research.

“Our strategy to identify gene network–correcting therapies that treat the core disease mechanism may represent a compelling path for drug discovery in a range of other human diseases. Many therapeutics found in the lab don’t translate well to humans or focus only on a specific symptom. We hope our approach can offer a new direction that could increase the likelihood of candidate therapies being effective in patients.”

In the same press release, Dr. Srivastava emphasizes the scientific advances that have driven the team’s research to this critical point.

“Our study is a really good example of how modern technologies are facilitating the kinds of discoveries that are possible today, but weren’t not so long ago. Using human iPSCs and gene editing allowed us to create a large number of cells that are relevant to the disease process, while powerful machine learning algorithms helped us identify, in a non-biased fashion, the important genes for distinguishing between healthy and diseased cells.”

The full results of this study were published in Science.

UCLA scientists discover how SARS-CoV-2 causes multiple organ failure in mice

Heart muscle cells in an uninfected mouse (left) and a mouse infected with SARS-CoV-2 (right) with mitochondria seen in pink. The disorganization of the cells and mitochondria in the image at right is associated with irregular heartbeat and death.
Image credit: UCLA Broad Stem Cell Center

As the worldwide coronavirus pandemic rages on, scientists are trying to better understand SARS-CoV-2, the virus that causes COVID-19, and the effects that it may have beyond those most commonly observed in the lungs. A CIRM-funded project at UCLA, co-led by Vaithilingaraja Arumugaswami, Ph.D. and Arjun Deb, M.D. discovered that SARS-CoV-2 can cause organ failure in the heart, kidney, spleen, and other vital organs of mice.

Mouse models are used to better understand the effects that a disease can have on humans. SARS-CoV-2 relies on a protein named ACE2 to infect humans. However, the virus doesn’t recognize the mouse version of the ACE2 protein, so healthy mice exposed to the SARS-CoV-2 virus don’t get sick.

To address this, past experiments by other research teams have genetically engineered mice to have the human version of the ACE2 protein in their lungs. These teams then infected the mice, through the nose, with the SARS-CoV-2 virus. Although this process led to viral infection in the mice and caused pneumonia, they don’t get as broad a range of other symptoms as humans do.

Previous research in humans has suggested that SARS-CoV-2 can circulate through the bloodstream to reach multiple organs. To evaluate this further, the UCLA researchers genetically engineered mice to have the human version of the ACE2 protein in the heart and other vital organs. They then infected half of the mice by injecting SARS-CoV-2 into their bloodstreams and compared them to mice that were not infected. The UCLA team tracked overall health and analyzed how levels of certain genes and proteins in the mice changed.

Within seven days, all of the mice infected with the virus had stopped eating, were completely inactive, and had lost an average of about 20% of their body weight. The genetically engineered mice that had not been infected with the virus did not lose a significant amount of weight. Furthermore, the infected mice had altered levels of immune cells, swelling of the heart tissue, and deterioration of the spleen. All of these are symptoms that have been observed in people who are critically ill with COVID-19.

What’s even more surprising is that the UCLA team also found that genes that help cells generate energy were shut off in the heart, kidney, spleen and lungs of the infected mice. The study also revealed that some changes were long-lasting throughout the organs in mice with SARS-CoV-2. Not only were genes turned off in some cells, the virus made epigenetic changes, which are chemical alterations to the structure of DNA that can cause more lasting effects. This might help explain why some people that have contracted COVID-19 have symptoms for weeks or months after they no longer have traces of the virus in their body.

In a UCLA press release, Dr. Deb discusses the importance and significance of their findings.

“This mouse model is a really powerful tool for studying SARS-CoV-2 in a living system. Understanding how this virus can hijack our cells might eventually lead to new ways to prevent or treat the organ failure that can accompany COVID-19 in humans.”

The full results of this study were published in JCI Insight.

Positive results from CIRM-funded LAD-I trial presented at the 62nd American Society of Hematology Annual Meeting

Gaurav Shah, M.D., CEO and President of Rocket Pharmaceuticals

Leukocyte Adhesion Deficiency-I (LAD-I) is a rare pediatric disease caused by a mutation in a specific gene that causes low levels of a protein called CD18. Due to low levels of CD18, the adhesion of immune cells is affected, which negatively impacts the body’s ability to combat infections.

Rocket Pharmaceuticals is conducting a CIRM-funded ($6.56 M) clinical trial that is testing a treatment that uses a gene therapy called RP-L201. The therapy uses a patient’s own blood stem cells and inserts a functional version of the gene.  These modified stem cells are then reintroduced back into the patient. The goal is to establish functional immune cells, enabling the body to combat infections. Previous studies have indicated that an increase in CD18 to 4-10% is associated with survival into adulthood. 

The company presented interim data from the trial at the 62nd American Society of Hematology (ASH) Annual Meeting in the form of an oral presentation. The data presented is from three pediatric patients with severe LAD-I, which is defined by CD18 expression of less than 2%. The patients were all treated with RP-L201. Patient One was 9-years of age at enrollment and had been followed for 12-months as of a cutoff date of November 2020. Patient Two was 3-years of age at enrollment and had been followed for over 6-months. Patient Three was 7-months of age at enrollment and was recently treated with RP-L201.

Key highlights from the presentation include:

  • RP-L201 was well tolerated, no safety issues reported with infusion or post-treatment
  • All patients achieved hematopoietic (blood) reconstitution within 5-weeks
    • 12 months post-treatment, Patient One demonstrated durable CD18 expression of approximately 40%,
    • 6-months post-treatment, Patient Two demonstrated CD18 expression of 23%
    • 2-months post-treatment, Patient Three demonstrated CD18 expression of 76%

In a press release from Rocket, Gaurav Shah, M.D., CEO and President of Rocket, expressed excitement about these results.

“…we continue to see encouraging evidence of efficacy for RP-L201 for the treatment of LAD-I. Patients have shown sustained CD18 expression of 23% to 40%, far exceeding the 4-10% threshold associated with survival into adulthood…”

To view the presentations at the conclusion of the oral presentation, click the link here.