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.

Month of CIRM: Battling COVID-19

All this month we are using our blog and social media to highlight a new chapter in CIRM’s life, thanks to the people of California 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.

Dr. John Zaia, City of Hope stem cell researcher

The news that effective vaccines have been developed to help fight COVID-19 was a truly bright spot at the end of a very dark year. But it will be months, in some countries years, before we have enough vaccines to protect everyone. That’s why it’s so important to keep pushing for more effective ways to help people who get infected with the virus.

One of those ways is in a clinical study that CIRM is funding with City of Hope’s Dr. John Zaia. Dr. Zaia and his team, in partnership with the Translational Genomics Research Institute (TGen) in Flagstaff, Arizona, are using something called convalescent plasma to try and help people who have contracted the virus. Here’s the website they have created for the study.

Plasma is a part of our blood that carries proteins, called antibodies, that help defend our bodies against viral infections. When a patient recovers from COVID-19, their blood plasma contains antibodies against the virus. The hope is that those antibodies can now be used as a potential treatment for COVID-19 to help people who are newly infected. 

To carry out the study they are using clinical trial sites around California, including some of the CIRM Alpha Stem Cell Network clinics.

For the study to succeed they’ll first need people who have recovered from the virus to donate blood. That’s particularly appropriate in January because this is National Volunteer Blood Donor Month.

The team has three elements to their approach:

  • A rapid-response screening program to screen potential COVID-19 convalescent plasma donors, particularly in underserved communities.
  • A laboratory center that can analyze the anti-SARS-CoV-2 antibodies properties in COVID-19 convalescent plasma.
  • An analysis of the clinical course of the disease in COVID-19 patients to identify whether antibody properties correlate with clinical benefit of COVID-19 convalescent plasma.

There’s reason to believe this approach might work. A study published this week in the New England Journal of Medicine, found that blood plasma from people who have recovered from COVID-19 can help older adults and prevent them from getting seriously ill with the virus if they get the plasma within a few days of becoming infected.

We are used to thinking of blood donations as being used to help people after surgery or who have been in an accident. In this study the donations serve another purpose, but one that is no less important. The World Health Organization describes blood as “the most precious gift that anyone can give to another person — the gift of life. A decision to donate your blood can save a life, or even several if your blood is separated into its components — red cells, platelets and plasma.”

That plasma could help in developing more effective treatments against the virus. Because until we have enough vaccines for everyone, we are still going to need as much help as we can get in fighting COVID-19. The recent surge in cases throughout the US and Europe are a reminder that this virus is far from under control. We have already lost far too many people. So, if you have recently recovered from the virus, or know someone who has, consider donating blood to this study. It could prove to be a lifesaver.

For more information about the study and how you can be part of it, click here.

Month of CIRM: Reviewing Review

Dr. Gil Sambrano, Vice President Portfolio & Review

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 look at our Review team.

Many people who have to drive every day don’t really think about what’s going on under the hood of their car. As long as the engine works and gets them from A to B, they’re happy. I think the same is true about CIRM’s Review team. Many people don’t really think about all the moving parts that go into reviewing a promising new stem cell therapy.

But that’s a shame, because they are really missing out on watching a truly impressive engine at work.

Just consider the simple fact that since CIRM started about 4,000 companies, groups and individuals have applied to us for funding. Just take a moment to consider that number. Four thousand. Then consider that at no time have there been more than 5 people working in the review team. That’s right. Just 5 people. And more recently there have been substantially fewer. That’s a lot of projects and not a lot of people to review them. So how do they do it? Easy. They’re brilliant.

First, as applications come in they are scrutinized to make sure they meet specific eligibility requirements; do they involve stem cells, is the application complete, is it the right stage of research, is the budget they are proposing appropriate for the work they want to do etc. If they pass that initial appraisal, they then move on to the second round, the Grants Working Group or GWG.

The GWG consists of independent scientific experts from all over the US, all over the world in fact. However, none are from California because we want to ensure there are no possible conflicts of interest. When I say experts, I do mean experts. These are among the top in their field and are highly sought after to do reviews with the National Institutes of Health etc.

Mark Noble, PhD, the Director of the Stem Cell and Regenerative Medicine Institute at the University of Rochester, is a long-time member of the GWG. He says it’s a unique group of people:

“It’s a wonderful scientific education because you come to these meetings and someone is putting in a grant on diabetes and someone’s putting in a  grant on repairing the damage to the heart or spinal cord injury or they have a device that will allow you to transplant cells better and there are people  in the room that are able to talk knowledgeably about each of these areas and understand how this plays into medicine and how it might work in terms of actual financial development and how it might work in the corporate sphere and how it fits in to unmet medical needs . I don’t know of any comparable review panels like this that have such a broad remit and bring together such a breadth of expertise which means that every review panel you come to you are getting a scientific education on all these different areas, which is great.”

The GWG reviews the projects for scientific merit: does the proposal seem plausible, does the team proposing it have the experience and expertise to do the work etc. The reviewers put in a lot of work ahead of time, not just reviewing the application, but looking at previous studies to see if the new application has evidence to support what this team hope to do, to compare it to other efforts in the same field. There are disagreements, but also a huge amount of respect for each other.

Once the GWG makes its recommendations on which projects to fund and which ones not to, the applications move to the CIRM Board, which has the final say on all funding decisions. The Board is given detailed summaries of each project, along with the recommendations of the GWG and our own CIRM Review team. But the Board is not told the identity of any of the applicants, those are kept secret to avoid even the appearance of any conflict of interest.

The Board is not required to follow the recommendations of the GWG, though they usually do. But the Board is also able to fund projects that the GWG didn’t place in the top tier of applications. They have done this on several occasions, often when the application targeted a disease or disorder that wasn’t currently part of the agency’s portfolio.

So that’s how Review works. The team, led by Dr. Gil Sambrano, does extraordinary work with little fanfare or fuss. But without them CIRM would be a far less effective agency.

The passage of Proposition 14 means we now have a chance to resume full funding of research, which means our Review team is going to be busier than ever. They have already started making changes to the application requirements. To help let researchers know what those changes are we are holding a Zoom webinar tomorrow, Thursday, at noon PST. If you would like to watch you can find it on our YouTube channel. And if you have questions you would like to ask send them to info@cirm.ca.gov

A Month of CIRM: Where we’ve been, where we’re going

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. We kick off this event with a letter from our the Chair of our Board, Jonathan Thomas.

When voters approved Proposition 14 last November, they gave the Stem Cell Agency a new lease on life and a chance to finish the work we began with the approval of Proposition 71 in 2004. It’s a great honor and privilege. It’s also a great responsibility. But I think looking back at what we have achieved over the last 16 years shows we are well positioned to seize the moment and take CIRM and regenerative medicine to the next level and beyond.

When we started, we were told that if we managed to get one project into a clinical trial by the time our money ran out we would have done a good job. As of this moment we have 68 clinical trials that we have funded plus another 31 projects in clinical trials where we helped fund crucial early stage research. That inexorable march to therapies and cures will resume when we take up our first round of Clinical applications under Prop 14 in March.

But while clinical stage projects are the end game, where we see if therapies really work and are safe in people, there’s so much more that we have achieved since we were created. We have invested $900 million in  basic research, creating a pipeline of the most promising stem cell research programs, as well as investing heavily on so-called “translational” projects, which move projects from basic science to where they’re ready to apply to the Food and Drug Administration (FDA) to begin clinical trials.

We have funded more than 1,000 projects, with each one giving us valuable information to help advance the science. Our funding has helped attract some of the best stem cell scientists in the world to California and, because we only fund research in California, it has persuaded many companies to either move here or open offices here to be eligible for our support. We have helped create the Alpha Stem Cell Clinics, a network of leading medical centers around the state that have the experience and expertise to deliver stem cell therapies to patients. All of those have made California a global center in the field.

That result is producing big benefits for the state. An independent Economic Impact Analysis reported that by the end of 2018 we had already helped generate an extra $10.7 billion in new sales revenue and taxes for California, hundreds of millions more in federal taxes and created more than 56,000 new jobs.

As if that wasn’t enough, we have also:

  • Helped develop the largest iPSC research bank in the world.
  • Created the CIRM Center of Excellence in Stem Cell Genomics to accelerate fundamental understanding of human biology and disease mechanisms.
  • Helped fund the construction of 12 world class stem cell institutes throughout the state.
  • Reached a unique partnership with the National Heart, Lung and Blood Institutes to find a cure for sickle cell disease.
  • Used our support for stem cell research to leverage an additional $12 billion in private funding for the field.
  • Enrolled more than 2700 patients in CIRM funded clinical trials

In many ways our work is just beginning. We have laid the groundwork, helped enable an extraordinary community of researchers and dramatically accelerated the field. Now we want to get those therapies (and many more) over the finish line and get them approved by the FDA so they can become available to many more people around the state, the country and the world.

We also know that we have to make these therapies available to all people, regardless of their background and ability to pay. We have to ensure that underserved communities, who were often left out of research in the past, are an integral part of this work and are included in every aspect of that research, particularly clinical trials. That’s why we now require anyone applying to us for funding to commit to engaging with underserved communities and to have a written plan to show how they are going to do that.

Over the coming month, you will hear more about some of the remarkable things we have managed to achieve so far and get a better sense of what we hope to do in the future. We know there will be challenges ahead and that not everything we do or support will work. But we also know that with the team we have built at CIRM, the brilliant research community in California and the passion and drive of the patient advocate community we will live up to the responsibility the people of California placed in us when they approved Proposition 14.

Inspiring new documentary about stem cell research

Poster for the documentary “Ending Disease”

2020 has been, to say the very least, a difficult and challenging year for all of us. But while the focus of the world has, understandably, been on the coronavirus there was also some really promising advances in stem cell research. Those advances are captured in a great new documentary called Ending Disease.

The documentary is by Emmy award-winning filmmaker Joe Gantz. In it he follows ten people who are facing life-threatening or life-changing diseases and injuries and who turn to pioneering stem cell therapies for help.

It’s an inspiring documentary, one that reminds you of the real need for new treatments and the tremendous hope and promise of stem cell therapies. Here’s a look at a trailer for Ending Disease.

You can see an exclusive screening of Ending Disease on Friday, January 8th, 2021 at 5:00pm PST.

After the livestream, there will be a live Q&A session where former members of the successful Proposition 14 campaign team – which refunded CIRM with an additional $5.5 billion – will be joined by CIRM’s President and CEO Dr. Maria Millan, talking about what lies ahead for CIRM and the future of stem cell research.

To purchase a ticket, click here. It only costs $12 and 50% of the ticket sales proceeds will go to Americans for Cures to help them continue to advocate for the advancement of stem cell research, and more importantly, for the patients and families to whom stem cell research provides so much hope.

If you need any extra persuading that it’s something you should definitely put on our calendar, here’s a letter from the film maker Joe Gantz.

I am the director of the documentary Ending Disease: The Stem Cell, Anti-Cancer T-Cell, & Antibody Revolution In Medicine, a film that will help inform people about the progress that’s been made in this field and how people with their lives on the line are now able to benefit from these new regenerative therapies. 

I was granted unprecedented access to ten of the first generation of clinical trials using stem cell and regenerative medicine to treat and cure many of the most devastating diseases and conditions including: brain cancer, breast cancer, leukemia and lymphoma, HIV, repairing a broken spinal cord, retinitis pigmentosa and SCID. The results are truly inspiring.

This is personal for me.  After spending four years making this documentary, I was diagnosed with bladder cancer. Upon diagnosis, I immediately felt the same desperation as millions of families who are in search of a medical breakthrough. I understood, on a personal level, what the patients we followed in the film all knew: when you are diagnosed with a disease, there is a narrow window of time in which you can effectively seek a life-saving treatment or cure. If treatment becomes available outside of that window, then it is too late. However, Ending Disease shows that with continued support for regenerative medicine, we can create a near future in which one-time cures and highly mitigating therapies are available to patients for a whole host of diseases.

Best regards,

Joe

“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.

Persistence pays off in search for clue to heart defects

A team of scientists led by Benoit Bruneau (left), including Irfan Kathiriya (center) and Kavitha Rao (right), make inroads into understanding what genes are improperly deployed in some cases of congenital heart disease.  Photo courtesy Gladstone Institute

For more than 20 years Dr. Benoit Bruneau has been trying to identify the causes of congenital heart disease, the most common form of birth defect in the U.S. It turns out that it’s not one cause, but many.

Congenital heart disease covers a broad range of defects, some relatively minor and others life-threatening and even fatal. It’s been known that a mutation in a gene called TBX5 is responsible for some of these defects, so, in a CIRM-funded study ($1.56 million), Bruneau zeroed in on this mutation to see if it could help provide some answers.

In the past Bruneau, the director of the Gladstone Institute of Cardiovascular Disease, had worked with a mouse model of TBX5, but this time he used human induced pluripotent stem cells (iPSCs). These are cells that can be manipulated in the lab to become any kind of cell in the human body. In a news release Bruneau says this was an important step forward.

“This is really the first time we’ve been able to study this genetic mutation in a human context. The mouse heart is a good proxy for the human heart, but it’s not exactly the same, so it’s important to be able to carry out these experiments in human cells.”

The team took some iPSCs, changed them into heart cells, and used a gene editing tool called CRISPR-Cas9 to create the kinds of mutations in TBX5 that are seen in people with congenital heart disease. What they found was some genes were affected a lot, some not so much. Which is what you might expect in a condition that causes so many different forms of problems.

“It makes sense that some are more affected than others, but this is the first experimental data in human cells to show that diversity,” says Bruneau.

But they didn’t stop there. Oh no. Then they did a deep dive analysis to understand how the different ways that different cells were impacted related to each other. They found some cells were directly affected by the TBX5 mutation but others were indirectly affected.

The study doesn’t point to a simple way of treating congenital heart disease but Bruneau says it does give us a much better understanding of what’s going wrong, and perhaps will give us better ideas on how to stop that.

“Our new data reveal that the genes are really all part of one network—complex but singular—which needs to stay balanced during heart development. That means if we can figure out a balancing factor that keeps this network functioning, we might be able to help prevent congenital heart defects.”

The study is published in the journal Developmental Cell.

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.