Time and money and advancing stem cell research

The human genome

Way back in the 1990’s scientists were hard at work decoding the human genome, trying to map and understand all the genes that make up people. At the time there was a sense of hope, a feeling that once we had decoded the genome, we’d have cures for all sorts of things by next Thursday. It didn’t quite turn out that way.

The same was true for stem cell research. In the early days there was a strong feeling that this was going to quite quickly produce new treatments and cures for diseases ranging from Parkinson’s and Alzheimer’s to heart disease and stroke. Although we have made tremendous strides we are still not where we hoped we’d be.

It’s a tough lesson to learn, but an important one: good scientific research moves at its own pace and pays little heed to our hopes or desires. It takes time, often a long time, and money, usually a lot of money, to develop new treatments for deadly diseases and disorders.

Many people, particularly those battling deadly diseases who are running out of time, are frustrated at the slow pace of stem cell research, at the years and years of work that it takes to get even the most promising therapy into a clinical trial where it can be tested in people. That’s understandable. If your life is on the line, it’s difficult to be told that you have to be patient. Time is a luxury many patients don’t have.

But that caution is necessary. The last thing we want to do is rush to test something in people that isn’t ready. And stem cells are a whole new way of treating disease, using cells that may stay in the body for years, so we really need to be sure we have done everything we can to ensure they are safe before delivering them to people.

The field of gene therapy was set back years after one young patient, Jesse Gelsinger, died as a result of an early experimental treatment. We don’t want the same to happen to stem cell research.

And yet progress is being made, albeit not as quickly as any of us would like. At the end of the first ten years of CIRM’s existence we had ten projects that we supported that were either in, or applying to be in, a clinical trial sanctioned by the US Food and Drug Administration (FDA). Five years later that number is 56.

Most of those are in Phase 1 or 2 clinical trials which means they are still trying to show they are both safe and effective enough to be made available to a wider group of people. However, some of our projects are in Phase 3, the last step before, hopefully, being given FDA approval to be made more widely available and – just as important – to be covered by insurance.

Other CIRM-funded projects have been given Regenerative Medicine Advanced Therapy (RMAT) designation by the FDA, a new program that allows projects that show they are safe and benefit patients in early stage clinical trials, to apply for priority review, meaning they could get approved faster than normal. Out of 40 RMAT designations awarded so far, six are for CIRM projects.

We are working hard to live up to our mission statement of accelerating stem cell treatments to patients with unmet medical needs. We have been fortunate in having $3 billion to spend on advancing this research in California; an amount no other US state, indeed few other countries, have been able to match. Yet even that amount is tiny compared to the impact that many of these diseases have. For example, the economic cost of treating diabetes in the US is a staggering $327 billion a year.

The simple truth is that unless we, as a nation, invest much more in scientific research, we are not going to be able to develop cures and new, more effective, treatments for a wide range of diseases.

Time and money are always going to be challenging when it comes to advancing stem cell research and bringing treatments to patients. With greater knowledge and understanding of stem cells and how best to use them we can speed up the timeline. But without money none of that can happen.

Our blog is just one of many covering the topic of “What are the hurdles impacting patient access to cell and gene therapies as part of Signal’s fourth annual blog carnival.

One family’s fight to save their son’s life, and how stem cells made it possible

CIRM’s mission is very simple: to accelerate stem cell treatments to patients with unmet medical needs. Anne Klein’s son, Everett, was a poster boy for that statement. Born with a fatal immune disorder Everett faced a bleak future. But Anne and husband Brian were not about to give up. The following story is one Anne wrote for Parents magazine. It’s testament to the power of stem cells to save lives, but even more importantly to the power of love and the determination of a family to save their son.

My Son Was Born With ‘Bubble Boy’ Disease—But A Gene Therapy Trial Saved His Life

Everett Schmitt. Photo: Meg Kumin

I wish more than anything that my son Everett had not been born with severe combined immunodeficiency (SCID). But I know he is actually one of the lucky unlucky ones. By Anne Klein

As a child in the ’80s, I watched a news story about David Vetter. David was known as “the boy in the bubble” because he was born with severe combined immunodeficiency (SCID), a rare genetic disease that leaves babies with very little or no immune system. To protect him, David lived his entire life in a plastic bubble that kept him separated from a world filled with germs and illnesses that would have taken his life—likely before his first birthday.

I was struck by David’s story. It was heartbreaking and seemed so otherworldly. What would it be like to spend your childhood in an isolation chamber with family, doctors, reporters, and the world looking in on you? I found it devastating that an experimental bone marrow transplant didn’t end up saving his life; instead it led to fatal complications. His mother, Carol Ann Demaret, touched his bare hand for the first and last time when he was 12 years old.

I couldn’t have known that almost 30 years later, my own son, Everett, would be born with SCID too.

Everett’s SCID diagnosis

At birth, Everett was big, beautiful, and looked perfectly healthy. My husband Brian and I already had a 2-and-a-half-year-old son, Alden, so we were less anxious as parents when we brought Everett home. I didn’t run errands with Alden until he was at least a month old, but Everett was out and about with us within a few days of being born. After all, we thought we knew what to expect.

But two weeks after Everett’s birth, a doctor called to discuss Everett’s newborn screening test results. I listened in disbelief as he explained that Everett’s blood sample indicated he may have an immune deficiency.

“He may need a bone marrow transplant,” the doctor told me.

I was shocked. Everett’s checkup with his pediatrician just two days earlier went swimmingly. I hung up and held on to the doctor’s assurance that there was a 40 percent chance Everett’s test result was a false positive.

After five grueling days of waiting for additional test results and answers, I received the call: Everett had virtually no immune system. He needed to be quickly admitted to UCSF Benioff Children’s Hospital in California so they could keep him isolated and prepare to give him a stem cell transplant. UCSF diagnosed him specifically with SCID-X1, the same form David battled.

Beginning SCID treatment

The hospital was 90 miles and more than two hours away from home. Our family of four had to be split into two, with me staying in the hospital primarily with Everett and Brian and Alden remaining at home, except for short visits. The sudden upheaval left Alden confused, shaken, and sad. Brian and I quickly transformed into helicopter parents, neurotically focused on every imaginable contact with germs, even the mildest of which could be life-threatening to Everett.

When he was 7 weeks old, Everett received a stem cell transplant with me as his donor, but the transplant failed because my immune cells began attacking his body. Over his short life, Everett has also spent more than six months collectively in the hospital and more than three years in semi-isolation at home. He’s endured countless biopsies, ultrasounds, CT scans, infusions, blood draws, trips to the emergency department, and medical transports via ambulance or helicopter.

Gene therapy to treat SCID

At age 2, his liver almost failed and a case of pneumonia required breathing support with sedation. That’s when a doctor came into the pediatric intensive care unit and said, “When Everett gets through this, we need to do something else for him.” He recommended a gene therapy clinical trial at the National Institutes of Health (NIH) that was finally showing success in patients over age 2 whose transplants had failed. This was the first group of SCID-X1 patients to receive gene therapy using a lentiviral vector combined with a light dose of chemotherapy.

After the complications from our son’s initial stem cell transplant, Brian and I didn’t want to do another stem cell transplant using donor cells. My donor cells were at war with his body and cells from another donor could do the same. Also, the odds of Everett having a suitable donor on the bone marrow registry were extremely small since he didn’t have one as a newborn. At the NIH, he would receive a transplant with his own, perfectly matched, gene-corrected cells. They would be right at home.

Other treatment options would likely only partially restore his immunity and require him to receive infusions of donor antibodies for life, as was the case with his first transplant. Prior gene therapy trials produced similarly incomplete results and several participants developed leukemia. The NIH trial was the first one showing promise in fully restoring immunity, without a risk of cancer. Brian and I felt it was Everett’s best option. Without hesitation, we flew across the country for his treatment. Everett received the gene therapy in September 2016 when he was 3, becoming the youngest patient NIH’s clinical trial has treated.

Everett’s recovery

It’s been more than two years since Everett received gene therapy and now more than ever, he has the best hope of developing a fully functioning immune system. He just received his first vaccine to test his ability to mount a response. Now 6 years old, he’s completed kindergarten and has been to Disney World. He plays in the dirt and loves shows and movies from the ’80s (maybe some of the same ones David enjoyed).

Everett knows he has been through a lot and that his doctors “fixed his DNA,” but he’s focused largely on other things. He’s vocal when confronted with medical pain or trauma, but seems to block out the experiences shortly afterwards. It’s sad for Brian and me that Everett developed these coping skills at such a young age, but we’re so grateful he is otherwise expressive and enjoys engaging with others. Once in the middle of the night, he woke us up as he stood in the hallway, exclaiming, “I’m going back to bed, but I just want you to know that I love you with all my heart!”

I wish more than anything that Everett had not been born with such a terrible disease and I could erase all the trauma, isolation, and pain. But I know that he is actually one of the lucky unlucky ones. Everett is fortunate his disease was caught early by SCID newborn screening, which became available in California not long before his birth. Without this test, we would not have known he had SCID until he became dangerously ill. His prognosis would have been much worse, even under the care of his truly brilliant and remarkable doctors, some of whom cared for David decades earlier.

Carol-Ann-mother-of-David-Vetter-meeting-Everett-Schmitt
Everett Schmitt meeting David Vetter’s mom Carol Ann Demaret. Photo – Brian Schmitt

When Everett was 4, soon after the gene therapy gave him the immunity he desperately needed, our family was fortunate enough to cross paths with David’s mom, Carol Ann, at an Immune Deficiency Foundation event. Throughout my life, I had seen her in pictures and on television with David. In person, she was warm, gracious, and humble. When I introduced her to Everett and explained that he had SCID just like David, she looked at Everett with loving eyes and asked if she could touch him. As she touched Everett’s shoulder and they locked eyes, Brian and I looked on with profound gratitude.

Anne Klein is a parent, scientist, and a patient advocate for two gene therapy trials funded by the California Institute for Regenerative Medicine. She is passionate about helping parents of children with SCID navigate treatment options for their child.

You can read about the clinical trials we are funding for SCID here, here, here and here.

HIV eliminated from mice using CRISPR and LASER ART

Dr. Kamel Khalili

In the United States alone, there are approximately 1.1 million people living with Human immunodeficiency virus (HIV), a virus that weakens the immune system by destroying important cells that fight off disease and infection. This number is much larger on a global scale, with 36.9 million people living with HIV as of 2017. If left untreated, the immune system becomes so weakened that the condition worsens into acquired immunodeficiency syndrome (AIDS), which is usually fatal.

Current treatment for HIV focuses on the use of antiretroviral therapy (ART). This treatment is able to suppress replication of the virus, but it does not eliminate it from the body entirely. In order to be sustainable, ART must be taken throughout the course of a lifetime, otherwise HIV rebounds and the replication of the virus renews, fueling the development of AIDS.

The ability of HIV to rebound is related to the fact that it is able to integrate its DNA into various cells inside the body and beyond the reach of ART. Here they are able to remain dormant and ready to replicate as soon as ART is not interfering. It is because of this that ART is not sufficient on its own to cure HIV, but a group of scientists have uncovered a promising breakthrough to change that.

In a major collaboration, researchers at the Lewis Katz School of Medicine at Temple University and the University of Nebraska Medical Center (UNMC) have for the first time eliminated HIV from the DNA of living mice. This study marks a critical step toward the development of a possible cure for human HIV infection.

The team of researchers was able to do this with the help of a new technology called long-acting slow-effective release (LASER) ART. LASER ART is able to target HIV sanctuaries and maintain replication at low levels for extended periods of time. Immediately after administering LASER ART, the team used a gene editing technology known as CRISPR to remove the final remnants of HIV DNA hidden inside cells.

In a press release, Dr. Kamel Khalili, senior investigator for this study, was quoted as saying,

“Our study shows that treatment to suppress HIV replication and gene editing therapy, when given sequentially, can eliminate HIV from cells and organs of infected animals…We now have a clear path to move ahead to trials in non-human primates and possibly clinical trials in human patients within the year.”

The full results of this study were published in Nature Communications.

To learn more about how CRISPR technology works, you can read more about it on a previous blog post.

“A new awakening”: One patient advocate’s fight for her daughters life

We often talk about the important role that patient advocates play in helping advance research. That was demonstrated in a powerful way last week when the CIRM Board approved almost $12 million to fund a clinical trial targeting a rare childhood disorder called cystinosis.

The award, to Stephanie Cherqui and her team at UC San Diego (in collaboration with UCLA) was based on the scientific merits of the program. But without the help of the cystinosis patient advocate community that would never have happened. Years ago the community held a series of fundraisers, bake sales etc., and used the money to help Dr. Cherqui get her research started.

That money enabled Dr. Cherqui to get the data she needed to apply to CIRM for funding to do more detailed research, which led to her award last week. There to celebrate the moment was Nancy Stack. Her testimony to the Board was a moving celebration of how long they have worked to get to this moment, and how much hope this research is giving them.

Nancy Stack is pictured in spring 2018 with her daughter Natalie Stack and husband Geoffrey Stack. (Lar Wanberg/Cystinosis Research Foundation)

Hello my name is Nancy Stack and I am the founder and president of the Cystinosis Research Foundation.  Our daughter Natalie was diagnosed with cystinosis when she was an infant. 

Cystinosis is a rare disease that is characterized by the abnormal accumulation of cystine in every cell in the body.  The build-up of cystine eventually destroys every organ in the body including the kidneys, eyes, liver, muscles, thyroid and brain.  The average age of death from cystinosis and its complications is 28 years of age.

For our children and adults with cystinosis, there are no healthy days. They take between 8-12 medications around the clock every day just to stay alive – Natalie takes 45 pills a day.  It is a relentless and devastating disease.

Medical complications abound and our children’s lives are filled with a myriad of symptoms and treatments – there are g-tube feedings, kidney transplants, bone pain, daily vomiting,  swallowing difficulties, muscle wasting, severe gastrointestinal side effects and for some blindness.   

We started the Foundation in 2003.  We have worked with and funded Dr. Stephanie Cherqui since 2006.   As a foundation, our resources are limited but we were able to fund the initial grants for Stephanie’s  Stem Cell studies. When CIRM awarded a grant to Stephanie in 2016, it allowed her to complete the studies, file the IND and as a result, we now have FDA approval for the clinical trial. Your support has changed the course of this disease. 

When the FDA approved the clinical trial for cystinosis last year, our community was filled with a renewed sense of hope and optimism.  I heard from 32 adults with cystinosis – all of them interested in the clinical trial.  Our adults know that this is their only chance to live a full life. Without this treatment, they will die from cystinosis.  In every email I received, there was a message of hope and gratitude. 

I received an email from a young woman who said this, “It’s a new awakening to learn this morning that human clinical trials have been approved by the FDA. I reiterate my immense interest to participate in this trial as soon as possible because my quality of life is at a low ebb and the trial is really my only hope. Time is running out”. 

And a mom of a 19 year old young man who wants to be the first patient in the trial wrote and said this, “On the day the trial was announced I started to cry tears of pure happiness and I thought, a mother somewhere gets to wake up and have a child who will no longer have cystinosis. I felt so happy for whom ever that mom would be….I never imagined that the mom I was thinking about could be me. I am so humbled to have this opportunity for my son to try to live disease free.

My own daughter ran into my arms that day and we cried tears of joy – finally, the hope we had clung to was now a reality. We had come full circle.  I asked Natalie how it felt to know that she could be cured and she said, “I have spent my entire life thinking that I would die from cystinosis in my 30s but now, I might live a full life and I am thinking about how much that changes how I think about my future. I never planned too far ahead but now I can”. 

As a mother, words can’t possible convey what it feels like to know that my child has a chance to live a long, healthy life free of cystinosis – I can breathe again. On behalf of all the children and adults with cystinosis, thank you for funding Dr. Cherqui, for caring about our community, for valuing our children and for making this treatment a reality.  Our community is ready to start this trial – thank you for making this happen.

*************

CIRM will be celebrating the role of patient advocates at a free event in Los Angeles tomorrow. It’s at the LA Convention Center and here are the details. And did I mention it’s FREE!

Tue, June 25, 2019 – 6:00 PM – 7:00 PM PDT

Petree Hall C., Los Angeles Convention Center, 1201 South Figueroa Street Los Angeles, CA 90015

And on Wednesday, USC is holding an event highlighting the progress being made in fighting diseases that destroy vision. Here’s a link to information about the event.

Stanford and University of Tokyo researchers crack the code for blood stem cells

Blood stem cells grown in lab

Blood stem cells offer promise for a variety of immune and blood related disorders such as sickle cell disease and leukemia. Like other stem cells, blood stem cells have the ability to generate additional blood stem cells in a process called self-renewal. Additionally, they are able to generate blood cells in a process called differentiation. These newly generated blood cells have the potential to be utilized for transplantations and gene therapies.

However, two limitations have hindered the progress made in this field. One problem relates to the amount of blood stem cells needed to make a potential transplantation or gene therapy viable. Unfortunately, it has been challenging to isolate and grow blood stem cells in large quantity needed for these approaches. A part of this reason relates to getting the blood stem cells to self-renew rather than differentiate.

The second problem involves the existing blood stem cells in the patient’s body prior to transplantation. In order for the procedure to work, the patient’s own blood stem cells must be eliminated to make space for the transplanted blood stem cells. This is done through a process known as conditioning, which typically involves chemotherapy and/or radiation. Unfortunately, chemotherapy and radiation can cause life-threatening side effects due to its toxicity, particularly in pediatric patients, such as growth retardation, infertility and secondary cancer in later life. Very sick or elderly patients are unable to tolerate this conditioning process, making them ineligible for transplants.

A CIRM funded study by a team at Stanford and the University of Tokyo has unlocked the code related to the generation of blood stem cells.

The collaborative team was able to modify the components used to grow blood stem cells. By making these modifications, which effects the growth and physical conditions of blood stem cells, the researchers have shown for the first time that it’s possible to get blood stem cells from mice to renew themselves hundreds or even thousands of times within a period of just 28 days. 

Furthermore, the team showed that when they transplanted the newly grown cells into mice that had not undergone conditioning, the donor cells had engrafted and remained functional.

The team also found that gene editing technology such as CRISPR could be used while growing an adequate supply of blood stem cells for transplantation. This opens the possibility of obtaining a patient’s own blood stem cells, correcting the problematic gene, and reintroducing these back to the patient.

The complete study was published in Nature.

In a news release, Dr. Hiromitsu Nakauchi, a senior author of the study, is quoted as saying,

“For 50 years, researchers from laboratories around the world have been seeking ways to grow these cells to large numbers. Now we’ve identified a set of conditions that allows these cells to expand in number as much as 900-fold in just one month. We believe this approach could transform how [blood] stem cell transplants and gene therapy are performed in humans.” 

CIRM-funded therapy helps “bubble babies” lead a normal life

Ja’Ceon Golden; ‘cured” of SCID

At CIRM we are very cautious about using the “c” word. Saying someone has been “cured” is a powerful statement but one that loses its meaning when over used or used inappropriately. However, in the case of a new study from U.C. San Francisco and St. Jude Children’s Research Hospital in Memphis, saying “cure” is not just accurate, it’s a celebration of something that would have seemed impossible just a few years ago.

The research focuses on children with a specific form of Severe Combined Immunodeficiency (SCID) called X-Linked SCID. It’s also known as “bubble baby” disease because children born with this condition lack a functioning immune system, so even a simple infection could be fatal and in the past they were kept inside sterile plastic bubbles to protect them.

In this study, published in the New England Journal of Medicine, researchers took blood stem cells from the child and, in the lab, genetically re-engineered them to correct the defective gene, and then infused them back into the child. Over time they multiplied and created a new blood supply, one free of the defect, which helped repair the immune system.

In a news release Dr. Ewelina Mamcarz, the lead author of the study, announced that ten children have been treated with this method.

“These patients are toddlers now, who are responding to vaccinations and have immune systems to make all immune cells they need for protection from infections as they explore the world and live normal lives. This is a first for patients with SCID-X1.”

The ten children were treated at both St. Jude and at UCSF and CIRM funded the UCSF arm of the clinical trial.

The story, not surprisingly, got a lot of attention in the media including this fine piece by CNN.

Oh, and by the way we are also funding three other clinical trials targeting different forms of SCID. One with UCLA’s Don Kohn,  one with Stanford’s Judy Shizuru, and one with UCSF’s Mort Cowan

200 years later, the search for a cure for Parkinson’s continues

On the surface, actor Michael J. Fox, singer Neil Diamond, civil rights activist Jesse Jackson and Scottish comedian Billy Connolly would appear to have little in common. Except for one thing. They all have Parkinson’s Disease (PD).

Their celebrity status has helped raise public awareness about the condition, but studies show that awareness doesn’t amount to an understanding of PD or the extent to which it impacts someone’s life. In fact a study in the UK found that many people still don’t think PD is a serious condition.

To try and help change that people around the world will be holding events today, April 11th, World Parkinson’s Day.

The disease was first described by James Parkinson in 1817 in “An Essay on the Shaking Palsy”. In the essay Parkinson described a pattern of trembling in the hands and fingers, slower movement and loss of balance. Our knowledge about the disease has advanced in the last 200 years and now there are treatments that can help slow down the progression of the disease. But those treatments only last for a while, and so there is a real need for new treatments.  

That’s what Jun Takahashi’s team at Kyoto University in Japan hope to provide. In a first-of-its-kind procedure they took skin cells from a healthy donor and reprogrammed them to become induced pluripotent stem cells (iPSCs), or stem cells that become any type of cell. These iPSCs were then turned into the precursors of dopamine-producing neurons, the cells destroyed by PD, and implanted into 12 brain regions known to be hotspots for dopamine production.

The procedure was carried out in October and the patient, a male in his 50s, is still healthy. If his symptoms continue to improve and he doesn’t experience any bad side effects, he will receive a second dose of dopamine-producing stem cells. Six other patients are scheduled to receive this same treatment.

Earlier tests in monkeys showed that the implanted stem cells improved Parkinson’s symptoms without causing any serious side effects.

Dompaminergic neurons derived from stem cells

Scientists at UC San Francisco are trying a different approach, using gene therapy to tackle one of the most widely recognized symptoms of PD, muscle movement.

In the study, published in the journal Annals of Neurology, the team used an inactive virus to deliver a gene to boost production of dopamine in the brain. In a Phase 1 clinical trial 15 patients, whose medication was no longer able to fully control their movement disorder, were treated with this approach. Not only were they able to reduce their medication – up to 42 percent in some cases – the medication they did take lasted longer before causing dyskinesia, an involuntary muscle movement that is a common side effect of the PD medication.

In a news article Dr. Chad Christine, the first author of the study, says this approach may also help reduce other symptoms.

“Since many patients were able to substantially reduce the amount of Parkinson’s medications, this gene therapy treatment may also help patients by reducing dose-dependent side effects, such as sleepiness and nausea.” 

At CIRM we have a long history of funding research into PD. Over the years we have invested more than $55 million to try and develop new treatments for the disease.

In June 2018, the CIRM Board awarded $5.8 million to UC San Francisco’s Krystof Bankiewicz and Cedars-Sinai’s Clive Svendsen. They are using neural progenitor cells, which have the ability to multiply and turn into other kinds of brain cells, and engineering them to express the growth factor GDNF which is known to protect the cells damaged in PD. The hope is that when transplanted into the brain of someone with PD, it will help slow down, or even halt the progression of the disease. 

The CIRM funding will hopefully help the team do the pre-clinical research needed to get the FDA’s go-ahead to test this approach in a clinical trial. 

David Higgins, CIRM Board member and Patient Advocate for Parkinson’s Disease

At the time of the award David Higgins, PhD, the CIRM Board Patient Advocate for Parkinson’s Disease, said: “One of the big frustrations for people with Parkinson’s, and their families and loved ones, is that existing therapies only address the symptoms and do little to slow down or even reverse the progress of the disease. That’s why it’s important to support any project that has the potential to address Parkinson’s at a much deeper, longer-lasting level.”

But we don’t just fund the research, we try to bring the scientific community together to help identify obstacles and overcome them. In March of 2013, in collaboration with the Center for Regenerative Medicine (CRM) of the National Institutes of Health (NIH), we held a two-day workshop on cell therapies for Parkinson’s Disease. The experts outlined the steps needed to help bring the most promising research to patients.

Around one million Americans are currently living with Parkinson’s Disease. Worldwide the number is more than ten million. Those numbers are only expected to increase as the population ages. There is clearly a huge need to develop new treatments and, hopefully one day, a cure.

Till then days like April 11th will be an opportunity to remind ourselves why this work is so important.

CRISPR-Cas9 101: an overview and the role it plays in developing therapies

Illustration courtesy of TED website

There has been a lot of conversation surrounding CRISPR-Cas9 in these recent months as well as many sensational news stories. Some of these stories highlight the promise this technology holds, while others emphasize a word of caution. But what exactly does this technology do and how does it work? Here is a breakdown that will help you better understand.

To start off, CRISPR is a naturally occurring process found in bacteria used as an immune system to defend against viruses. CRISPR simply put, are strands of DNA segments that contain repeating patterns. There are “scissor like” CRISPR proteins that have the ability to cut DNA segments. When a copy of a virus enters the bacteria, these “scissor like” proteins cut a segment of DNA from the virus and insert it into CRISPR. A copy of the viral DNA is made and another “attack” protein known as Cas9 attaches to it. By binding to the viral copy, Cas9 is able to sense that virus. When the same virus tries to enter the bacteria, Cas9 is able to seek and destroy it.

You can view a more detailed video explaining this concept below.

Many scientists analyzed this process in detail and it was eventually discovered that this CRISPR-Cas9 complex could be used to removed unwanted genes and insert a corrected copy, revolutionizing the way that we view the approach towards treating a wide variety of genetic diseases.

In fact, researchers at the Dana-Farber/Boston Children’s Cancer and Blood Disorders Center and the University of Massachusetts Medical School have developed a strategy using this complex to treat two inherited, lethal blood disorders, sickle cell disease (SCD) and beta thalassemia. Both of these diseases involve a mutation that effects production of red blood cells, which are produced by blood stem cells. In beta-thalassemia, the mutation prevent red blood cells from being able to carry enough oxygen, leading to anemia. In SCD, the mutations cause red blood cells to take on a “sickle” shape which can block blood vessels.

By using CRISPR-Cas9 to insert a corrected copy of the gene into a patient’s own blood stem cells, this team demonstrated that functional red blood cells can then be produced. These results pay the way for other blood disorders as well.

In a press release , Dr. Daniel Bauer, an attending physician with Dana-Farber and a senior author on both of these studies stated that,

“Combining gene editing with an autologous stem-cell transplant could be a therapy for sickle-cell disease, beta-thalassemia and other blood disorders.”

In a separate study, scientists at University of Massachusetts Medical School have developed a strategy that could be used to treat genetic disorders associated with unintentional repeats or copies of small DNA segments. These problematic small segments of DNA are called microduplications and cause as many as 143 different diseases, including limb-girdle muscular dystrophy, Hermansky-Pudlak syndrome, and Tay-Sachs.

Because these are issues caused by repeats or copies of small DNA segments, the CRISPR-Cas9 complex can be used to remove microduplications without having to insert any additional genetic material.

Dr. Scot A. Wolfe, a co-investigator of this study, stated that,

“It’s like hitting the reset button. We don’t have to add any corrective genetic material, instead the cell stitches the DNA back together minus the duplication. It’s a shortcut for gene correction with potential therapeutic appeal.”

Although there has been a lot progress made with this technology, there are still concerns that need to be addressed. An article in Science mentions how two studies have shown that CRISPR can still make unintended changes to DNA, which can be potentially dangerous. In the article, Dr. Jin-Soo Kim, a CRISPR researcher at Seoul National University is quoted as saying,

“It is now important to determine which component is responsible for the collateral mutations and how to reduce or avoid them.”

Overall, CRISPR-Cas9 has revolutionized the approach of precision medicine. A wide variety of diseases are caused by small, unexpected segments of DNA. By applying this approach found in bacteria to humans, we have uncovered a way to correct these segments at the microscopic level. However, there is still much that needs to be learned and perfected before it can be utilized in patients.

Promising start to CIRM-funded trial for life-threatening blood disorder

Aristotle

At CIRM we are always happy to highlight success stories, particularly when they involve research we are funding. But we are also mindful of the need not to overstate a finding. To quote the Greek philosopher Aristotle (who doesn’t often make an appearance on this blog), “one swallow does not a summer make”. In other words, one good result doesn’t mean you have proven something works.  But it might mean that you are on the right track. And that’s why we are welcoming the news about a clinical trial we are funding with Sangamo Therapeutics.  

The trial is for the treatment of beta-thalassemia, (beta-thal) a severe form of anemia caused by a genetic mutation. People with beta-thal require life-long blood transfusions because they have low levels of hemoglobin, a protein needed to help the blood carry oxygen around the body. Those low levels of oxygen can cause anemia, fatigue, weakness and, in severe cases, can lead to organ damage and even death. The life expectancy for people with the more severe forms of the condition is only 30-50 years.

In this clinical trial the Sangamo team takes a patient’s own blood stem cells and, using a gene-editing technology called zinc finger nuclease (ZFN), inserts a working copy of the defective hemoglobin gene. These modified cells are given back to the patient, hopefully generating a new, healthy, blood supply which potentially will eliminate the need for chronic blood transfusions.

Yesterday, Sangamo announced that the first patient treated in this clinical trial seems to be doing rather well.

The therapy, called ST-400, was given to a patient who has the most severe form of beta-thal. In the two years before this treatment the patient was getting a blood transfusion every other week. While the treatment initially caused an allergic reaction, the patient quickly rebounded and in the seven weeks afterwards:

  • Demonstrated evidence of being able to produce new blood cells including platelets and white blood cells
  • Showed that the genetic edits made by ST-400 were found in new blood cells
  • Hemoglobin levels – the amount of oxygen carried in the blood – improved.

In the first few weeks after the therapy the patient needed some blood transfusions but in the next five weeks didn’t need any.

Obviously, this is encouraging. But it’s also just one patient. We don’t yet know if this will continue to help this individual let alone help any others. A point Dr. Angela Smith, one of the lead researchers on the project, made in a news release:

“While these data are very early and will require confirmation in additional patients as well as longer follow-up to draw any clinical conclusion, they are promising. The detection of indels in peripheral blood with increasing fetal hemoglobin at seven weeks is suggestive of successful gene editing in this transfusion-dependent beta thalassemia patient. These initial results are especially encouraging given the patient’s β0/ β0 genotype, a patient population which has proved to be difficult-to-treat and where there is high unmet medical need.” It’s a first step. But a promising one. And that’s always a great way to start.

Rats, research and the road to new therapies

Don Reed

Don Reed has been a champion of CIRM even before there was a CIRM. He’s a pioneer in pushing for funding for stem cell research and now he’s working hard to raise awareness about the difference that funding is making.

In a recent article on Daily Kos, Don highlighted one of the less celebrated partners in this research, the humble rat.

A BETTER RAT? Benefit #62 of the California Stem Cell Agency

By Don C. Reed

When I told my wife Gloria I was writing an article about rats, she had several comments, including: “Oo, ugh!” and also “That’s disgusting!”

Obviously, there are problems with rats, such as when they chew through electrical wires, which may cause a short circuit and burn down the house. Also, they are blamed for carrying diseased fleas in their ears and spreading the Black Plague, which in 1340 killed half of China and one-third of Europe—but this is not certain. The plague may in fact have been transmitted by human-carried parasites.

But there are positive aspects to rats as well. For instance: “…a rat paired with  another that has a disability…will be very kind to the other rat. Usually, help is offered with food, cleaning, and general care.”—GUIDE TO THE RAT, by Ginger Cardinal.

Above all, anyone who has ever been sick owes a debt to rats, specifically the Norway rat with that spectacular name, rattus norvegicus domesticus, found in labs around the world.

I first realized its importance on March 1, 2002, when I held in my hand a rat which had been paralyzed, but then recovered the use of its limbs.

The rat’s name was Fighter, and she had been given a derivative of embryonic stem cells, which restored function to her limbs. (This was the famous stem cell therapy begun by Hans Keirstead with a Roman Reed grant, developed by Geron, and later by CIRM and Asterias, which later benefited humans.)

As I felt the tiny muscles struggling to be free, it was like touching tomorrow— while my paralyzed son, Roman Reed, sat in his wheelchair just a few feet away.

Was it different working with rats instead of mice? I had heard that the far smaller lab mice were more “bitey” than rats.  

Wanting to know more about the possibilities of a “better rat”, I went to the CIRM website, (www.cirm.ca.gov) hunted up the “Tools and Technology III” section, and the following complicated sentence::

“Embryonic stem cell- based generation of rat models for assessing human cellular therapies.”

Hmm. With science writing, it always takes me a couple of readings to know what they were talking about. But I recognized some of the words, so that was a start.

“Stemcells… rat models… human therapies….”  

I called up Dr. Qilong Ying, Principle Investigator (PI) of the study.

As he began to talk, I felt a “click” of recognition, as if, like pieces of a puzzle, facts were fitting together.

It reminded me of Jacques Cousteau, the great underwater explorer, when he tried to invent a way to breathe underwater. He had the compressed air tank, and a mouthpiece that would release air—but it came in a rush, not normal breathing.

So he visited his friend, race car mechanic Emil Gagnan, and told him, “I need something that will give me air, but only when I inhale,”– and Gagnan said: “Like that?” and pointed to a metal contraption on a nearby table.

It was something invented for cars. But by adding it to what Cousteau already had, the Cousteau-Gagnan SCUBA (Self Contained Underwater Breathing Apparatus) gear was born—and the ocean could now be explored.

Qi-Long Ying’s contribution to science may also be a piece of the puzzle of cure…

A long-term collaboration with Dr. Austin Smith centered on an attempt to do with rats what had done with mice.

In 2007, the  Nobel Prize in Medicine had been won by Dr. Martin Evans, Mario Capecchi, and Oliver Smithies. Working independently, they developed “knock-out” and “knock-in” mice, meaning to take out a gene, or put one in.  

But could they do the same with rats?

 “We and others worked very, very hard, and got nowhere,” said Dr. Evans.

Why was this important?

Many human diseases cannot be mimicked in the mouse—but might be in the rat. This is for several reasons: the rat is about ten times larger; its internal workings are closer to those of a human; and the rat is considered several million years closer (in evolutionary terms) to humans than the mouse.

In 2008 (“in China, that is the year of the rat,” noted Dr. Ying in our conversation) he received the first of three grants from CIRM.

“We proposed to use the classical embryonic stem cell-based gene-targeting technology to generate rat models mimicking human heart failure, diabetes and neurodegenerative diseases…”

How did he do?

In 2010, Science Magazine honored him with inclusion in their “Top 10 Breakthroughs for using embryonic stem cell-based gene targeting to produce the world’s first knockout rats, modified to lack one or more genes…”

And in 2016, he and Dr. Smith received the McEwen Award for Innovation,  the highest honor bestowed by the International Society for Stem Cell Research (ISSCR).

Using knowledge learned from the new (and more relevant to humans) lab rat, it may be possible to develop methods for the expansion of stem cells directly inside the patient’s own bone marrow. Stem cells derived in this fashion would be far less likely to be rejected by the patient.  To paraphrase Abraham Lincoln, they would be “of the patient, by the patient and for the patient—and shall not perish from the patient”—sorry!

Several of the rats generated in Ying’s lab (to mimic human diseases) were so successful that they have been donated to the Rat Research Resource center so that other scientists can use them for their study.

“Maybe in the future we will develop a cure for some diseases because of knowledge from using rat models,” said Ying. “I think it’s very possible. So we want more researchers from USC and beyond to come and use this technology.”

And it all began with the humble rat…