Retooling a COVID drug to boost its effectiveness

Coronavirus particles, illustration.

When the COVID-19 pandemic broke out scientists scrambled to find existing medications that might help counter the life-threatening elements of the virus. One of the first medications that showed real promise was remdesivir. It’s an anti-viral drug that was originally developed to target novel, emerging viruses, viruses like COVID19. It was approved for use by the Food and Drug Administration (FDA) in October 2020.

Remdesivir showed real benefits for some patients, reducing recovery time for those in the hospital, but it also had problems. It had to be delivered intravenously, meaning it could only be used in a hospital setting. And it was toxic if given in too high a dose.

In a new study – partially funded by CIRM (DISC2 COVID19-12022 $228,229) – researchers at the University of California San Diego (UCSD) found that by modifying some aspects of remdesivir they were able to make it easier to take and less toxic.

In a news release about the work Dr. Robert Schooley, a first author on the study, says we still need medications like this.

“Although vaccine development has had a major impact on the epidemic, COVID-19 has continued to spread and cause disease — especially among the unvaccinated. With the evolution of more transmissible viral variants, breakthrough cases of COVID are being seen, some of which can be severe in those with underlying conditions. The need for effective, well-tolerated antiviral drugs that can be given to patents at high risk for severe disease at early stages of the illness remains high.”

To be effective remdesivir must be activated by several enzymes in the body. It’s a complex process and explains why the drug is beneficial for some areas, such as the lung, but can be toxic to other areas, such as the liver. So, the researchers set out to overcome those problems.

The team created what are called lipid prodrugs, these are compounds that do not dissolve in water and are used to improve how a drug interacts with cells or other elements; they are often used to reduce the bad side effects of a medication. By inserting a modified form of remdesivir into this lipid prodrug, and then attaching it to an enzyme called a lipid-phosphate (which acts as a delivery system, bringing along the remdesivir prodrug combo), they were able to create an oral form of remdesivir.

Dr. Aaron Carlin, a co-first author of the study, says they were trying to create a hybrid version of the medication that would work equally well regardless of the tissue it interacted with.

“The metabolism of remdesivir is complex, which may lead to variable antiviral activity in different cell types. In contrast, these lipid-modified compounds are designed to be activated in a simple uniform manner leading to consistent antiviral activity across many cell types.”

When they tested the lipid prodrugs in animal models and human cells they found they were effective against COVID-19 in different cell types, including the liver. They are now working on further developing and testing the lipid prodrug to make sure it’s safe for people and that it can live up to their hopes of reducing the severity of COVID-19 infections and speed up recovery.

The study is published in the journal Antimicrobial Agents and Chemotherapy.

Friends, Romans, countrymen, lend me your ears – we have a podcast for you.

It seems like everyone, including my dog Freddie, has a podcast these days. So now we do too.

According to the Podcasthosting.org website there are some two million podcasts in the world. Make that two million and one. That’s because CIRM is launching its own podcast and doing it with one of the biggest names in biotech.

Our podcast is called – with a nod to The Who – “Talking ’bout (Re)Generation” and the first episode features our President & CEO Dr. Maria Millan interviewing Dr. Derrick Rossi, the co-founder of Moderna. Moderna, as I am sure you know, is the maker of one of the most effective vaccines against COVID.

In the interview Dr. Rossi talks about his early days as a postdoc at Stanford – supported by CIRM – and the career arc that led him to help create the company behind the vaccine, and what his plans are for the future. It’s a fun, chatty, lively interview; one you can listen to in the car, at home or wherever you listen to your podcasts.

We want the podcast to be fun for your ear holes and interesting and engaging for your brain. We’re going to be talking to scientists and researchers, doctors and nurses, patients and patient advocates and anyone else we think has something worth listening to.

We have other episodes planned and will share those with you in the near future. In the meantime, if you have any ideas or individuals you think would make a good subject for a podcast let us know, we are always happy to hear from you.

In the meantime, enjoy the show.

CIRM funding helps identify potential COVID-19 treatment

The steps of the virus growth cycle that can be targeted with therapies: The virus enters a host cell (1), the virus’s genetic instructions are released, taking over cellular machinery (2), the virus is replicated within the cell (3) and copies of the virus exit the cell in search of new host cells to infect (4). Drugs like berzosertib might disrupt steps 2 and 3.  Image credit: Marc Roseboro/California NanoSytems Institute at UCLA

During the global pandemic, many researchers have responded to the needs of patients severely afflicted with COVID-19 by repurposing existing therapies being developed to treat patients.  CIRM responded immediately to the pandemic and to researchers wanting to help by providing $5 million in emergency funding for COVID-19 related projects. 

One of these grants ($349,999), awarded to Dr. Vaithilingaraja Arumugaswami at UCLA, has aided a study that has singled out a compound that shows promise for treating SARS-CoV-2, the virus that causes COVID-19.

In the spirit of banding together to help patients severely affected by COVID-19, the project was a collaboration among scientists from UCLA and other universities in California, Delaware and Germany, as well as a German pharmaceutical company.

The compound is named berzosertib and is licensed by the company Merck KGaA in Darmstadt, Germany.  Prior to the pandemic, it was developed for potential use, in combination with chemotherapy, as a possible treatment for small-cell lung cancer, ovarian cancer, and other types of solid tumors.

The team screened 430 drugs from among the approximately 200,000 compounds in CNSI’s Molecular Screening Shared Resource libraries before zeroing in on berzosertib as the most promising candidate.  They limited their search to compounds that either had been approved, or are already in the process of being evaluated, for safety in humans.

In a press release from UCLA, Dr. Arumugawami explains the rationale behind screening a potential drug candidate.

“That way, the compounds have cleared the first regulatory hurdle and could be deployed for further clinical trials on COVID-19 faster than drugs that have not been tested in humans.”

The researchers, led by Dr. Arumugaswami and Dr. Robert Damoiseaux from UCLA, conducted a series of experiments using different cell types in lab dishes to look at how effective the compound was at blocking SARS-CoV-2 from replicating.  Unlike other approaches which attack the virus directly, targeting replication could help better address the ability of the virus to mutate. 

For this study, the team used cells from the kidney, heart and lungs, all of which are organs that the virus is known to attack. The researchers pretreated cells with berzosertib, exposed the cells to SARS-CoV-2, allowed 48 hours for infection to set in, and then evaluated the results.

The team found that the compound consistently stalled SARS-CoV-2 replication without damaging the cells. The scientists also tested the drug against SARS and MERS, both of which are other types of coronaviruses that triggered deadly outbreaks earlier in the 2000s. They found that it was effective in stopping the replication of those viruses as well.

In the same press release from UCLA, Dr. Damoiseaux expressed optimism for what these findings could mean as a potential treatment.

“This is a chance to actually find a drug that might be broader in spectrum, which could also help fight coronaviruses that are yet to come.”

The next steps for this research would be to explore the mechanism through which the compound blocks coronavirus replication.  Understanding this and conducting preclinical studies are both necessary before the compound could be tested in clinical trials for COVID-19.

The full results of this study were published in Cell Reports.

The study’s co-corresponding author is Ulrich Betz of Merck KGaA, Darmstadt, Germany; the company also provided partial funding and clinical-grade berzosertib for the research. Other co-authors are from UCLA, Cedars-Sinai Medical Center, UC Irvine, University of Delaware, the Leibniz Institute for Experimental Virology in Germany, Heidelberg University in Germany and Scripps Research Institute.

In addition to CIRM, the study was also funded by CNSI, the Broad Stem Cell Research Center, the David Geffen School of Medicine at UCLA, the National Eye Institute, and the Bill and Melinda Gates Foundation.

A word from our Chair, several in fact

In 2005, the New Oxford American Dictionary named “podcast” its word of the year. At the time a podcast was something many had heard of but not that many actually tuned in to. My how times have changed. Now there are some two million podcasts to chose from, at least according to the New York Times, and who am I to question them.

Yesterday, in the same New York Times, TV writer Margaret Lyons, wrote about how the pandemic helped turn her from TV to podcasts: “Much in the way I grew to prefer an old-fashioned phone call to a video chat, podcasts, not television, became my go-to medium in quarantine. With their shorter lead times and intimate production values, they felt more immediate and more relevant than ever before.”

I mention this because an old colleague of ours at CIRM, Neil Littman, has just launched his own podcast and the first guest on it was Jonathan Thomas, Chair of the CIRM Board. Their conversation ranged from CIRM’s past to the future of the regenerative field as a whole, with a few interesting diversions along the way. It’s fun listening. And as Margaret Lyons said it might be more immediate and more relevant than ever before.

Scientists look at how the lung and brain respond differently to SARS-CoV-2 infection

UC San Diego School of Medicine researchers found approximately 10-fold higher SARS-CoV-2 infection (green) in lung organoids (left), compared to brain organoids (right). Image courtesy of UCSD Health

Since the start of the coronavirus pandemic early last year, scientists all over the world are still trying to better understand SARS-CoV-2, the virus that causes COVID-19. Although the more commonly known symptoms involve respiratory issues, there have been other long term problems observed in recovered patients. These consist of heart issues, fatigue, and neurological issues such as loss of taste and smell and “brain fog”.

To better understand this, Dr. Tariq Rana and a team of researchers at the UC San Diego School of Medicine are using stem cells to create lung and brain organoids to better understand how the virus interacts with the various organ systems and to better develop therapies that block infection. Organoids are 3D models made of cells that can be used to analyze certain features of the human organ being modeled. Although they are far from perfect replicas, they can be used to study physical structure and other characteristics. 

The team’s lung and brain organoids produced molecules ACE2 and TMPRSS2, which sit like doorknobs on the outer surfaces of cells. SARS-CoV-2 is able to use these doorknobs to enter cells and establish infection.

Dr. Rana and his team then developed a pseudovirus, a noninfectious version of SARS-CoV-2, and attached a fluorescent label, allowing them to measure how effectively the virus binds in human lung and brain organoids as well as to evaluate the cells’ response. The team was surprised to see an approximately 10-fold higher SARS-CoV-2 infection in lung organoids compared to brain organoids. Additionally, treatment with TMPRSS2 inhibitors reduced infection levels in both organoids.

Besides differences in infection levels, the lung and brain organoids also differed in their responses to the virus. Infected lung organoids pumped out molecules intended to summon help from the immune system while infected brain organoids upped their production of molecules that plays a fundamental role in pathogen recognition and activation of the body’s own immune defenses.

In a news release from UC San Diego Health, Dr. Rana elaborates on the results of his study.

“We’re finding that SARS-CoV-2 doesn’t infect the entire body in the same way. In different cell types, the virus triggers the expression of different genes, and we see different outcomes.”

The next steps for Rana and his team is to develop SARS-CoV-2 inhibitors and test out how well they work in organoid models derived from people of a variety of racial and ethnic backgrounds that represent California’s diverse population. To carry out this research, CIRM awarded Dr. Rana a grant of $250,000, which is part of the $5 million in emergency funding for COVID-19 research that CIRM authorized at the beginning of the pandemic.

The full results of this study can be found in Stem Cell Reports.

Charting a course for the future

A new home for stem cell research?

Have you ever been at a party where someone says “hey, I’ve got a good idea” and then before you know it everyone in the room is adding to it with ideas and suggestions of their own and suddenly you find yourself with 27 pages of notes, all of them really great ideas. No, me neither. At least, not until yesterday when we held the first meeting of our Scientific Strategy Advisory Panel.

This is a group that was set up as part of Proposition 14, the ballot initiative that refunded CIRM last November (thanks again everyone who voted for that). The idea was to create a panel of world class scientists and regulatory experts to help guide and advise our Board on how to advance our mission. It’s a pretty impressive group too. You can see who is on the SSAP here.  

The meeting involved some CIRM grantees talking a little about their work but mostly highlighting problems or obstacles they considered key issues for the future of the field as a whole. And that’s where the ideas and suggestions really started flowing hard and fast.

It started out innocently enough with Dr. Amander Clark of UCLA talking about some of the needs for Discovery or basic research. She advocated for a consortium approach (this quickly became a theme for many other experts) with researchers collaborating and sharing data and findings to help move the field along.

She also called for greater diversity in research, including collecting diverse cell samples at the basic research level, so that if a program advanced to later stages the findings would be relevant to a wide cross section of society rather than just a narrow group.

Dr. Clark also said that as well as supporting research into neurodegenerative diseases, such as Alzheimer’s and Parkinson’s, there needed to be a greater emphasis on neurological conditions such as autism, bipolar disorder and other mental health problems.

(CIRM is already committed to both increasing diversity at all levels of research and expanding mental health research so this was welcome confirmation we are on the right track).

Dr. Mike McCun called for CIRM to take a leadership role in funding fetal tissue research, things the federal government can’t or won’t support, saying this could really help in developing an understanding of prenatal diseases.

Dr. Christine Mummery, President of ISSCR, advocated for support for early embryo research to deepen our understanding of early human development and also help with issues of infertility.

Then the ideas started coming really fast:

  • There’s a need for knowledge networks to share information in real-time not months later after results are published.
  • We need standardization across the field to make it easier to compare study results.
  • We need automation to reduce inconsistency in things like feeding and growing cells, manufacturing cells etc.
  • Equitable access to CRISPR gene-editing treatments, particularly for underserved communities and for rare diseases where big pharmaceutical companies are less likely to invest the money needed to develop a treatment.
  • Do a better job of developing combination therapies – involving stem cells and more traditional medications.

One idea that seemed to generate a lot of enthusiasm – perhaps as much due to the name that Patrik Brundin of the Van Andel Institute gave it – was the creation of a CIRM Hotel California, a place where researchers could go to learn new techniques, to share ideas, to collaborate and maybe take a nice cold drink by the pool (OK, I just made that last bit up to see if you were paying attention).

The meeting was remarkable not just for the flood of ideas, but also for its sense of collegiality.  Peter Marks, the director of the Food and Drug Administration’s Center for Biologics Evaluation and Research (FDA-CBER) captured that sense perfectly when he said the point of everyone working together, collaborating, sharing information and data, is to get these projects over the finish line. The more we work together, the more we will succeed.

Everything you wanted to know about COVID vaccines but never got a chance to ask

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 feature a rare treat, an interview with Moderna’s Dr. Derrick Rossi.

Moderna co-founder Dr. Derrick Rossi

It’s not often you get a chance to sit down with one of the key figures in the fight against the coronavirus and get to pick his brain about the best ways to beat it. We were fortunate enough to do that on Wednesday, talking to Dr. Derrick Rossi, the co-founder of Moderna, about the vaccine his company has developed.

CIRM’s President and CEO, Dr. Maria Millan, was able to chat to Dr. Rossi for one hour about his background (he got support from CIRM in his early post-doctoral research at Stanford) and how he and his colleagues were able to develop the COVID-19 vaccine, how the vaccine works, how effective it is, how it performs against new variations of the virus.

He also told us what he would have become if this science job hadn’t worked out.

All in all it was a fascinating conversation with someone whose work is offering a sense of hope for millions of people around the world.

If you missed it first time around you can watch it here.

How a CIRM scholar helped create a life-saving COVID vaccine

Dr. Derrick Rossi might be the most famous man whose name you don’t recognize. Dr. Rossi is the co-founder of Moderna. Yes, that Moderna. The COVID-19 vaccine Moderna. The vaccine that in clinical trials proved to be around 95 percent effective against the coronavirus.

Dr. Rossi also has another claim to fame. He is a former CIRM scholar. He did some of his early research, with our support, in the lab of Stanford’s Dr. Irv Weissman.

So how do you go from a lowly post doc doing research in what, at the time, was considered a rather obscure scientific field, to creating a company that has become the focus of the hopes of millions of people around the world?  Well, join us on Wednesday, January 27th at 9am (PST) to find out.

CIRM’s President and CEO, Dr. Maria Millan, will hold a live conversation with Dr. Rossi and we want you to be part of it. You can join us to listen in, and even post questions for Dr. Rossi to answer. Think of the name dropping credentials you’ll get when say to your friends; “Well, I asked Dr. Rossi about that and he told me…..”

Being part of the conversation is as simple as clicking on this link:

After registering, you will receive a confirmation email containing information about joining the webinar.

We look forward to seeing you there.

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.

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.