Researchers develop a stem cell-based implant for cartilage restoration and treating osteoarthritis

The Plurocart’s scaffold membrane seeded with stem cell-derived chondrocytes. Image courtesy of USC Photo/Denis Evseenko.

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Researchers at the Keck School of Medicine of USC have used a stem cell-based bio-implant to repair cartilage and delay joint degeneration in a large animal model. This paves the way to potentially treat humans with cartilage injuries and osteoarthritis, which occurs when the protective cartilage at the ends of the bones wears down over time. The disorder affects millions worldwide.

 The researchers are using this technology to manufacture the first 64 implants to be tested on humans with support from a $6 million grant from the California Institute for Regenerative Medicine (CIRM).

Researchers Dr. Denis Evseenko, and Dr. Frank Petrigliano led the development of the therapeutic bio-implant, called Plurocart. It’s composed of a scaffold membrane seeded with stem cell-derived chondrocytes, the cells responsible for producing and maintaining healthy articular cartilage tissue. 

In the study, the researchers implanted the Plurocart membrane into a pig model of osteoarthritis, resulting in the long-term repair of articular cartilage defects. Evseenko said the findings are significant because the implant fully integrated in the damaged articular cartilage tissue and survived for up to six months. “Previous studies have not been able to show survival of an implant for such a long time,” Evseenko added.

The researchers also found that the cartilage tissue generated was strong enough to withstand compression and elastic enough to accommodate movement without breaking.

Osteoarthritis, an often-painful disorder, can affect any joint, but most commonly affects those in our knees, hips, hands and spine. The USC researchers hope their implant will help prevent the development of arthritis and alleviate the need for invasive joint replacement surgeries.

“Many of the current options for cartilage injury are expensive, involve complex logistical planning, and often result in incomplete regeneration,” said Petrigliano. “Plurocart represents a practical, inexpensive, one-stage therapy that may be more effective in restoring damaged cartilage and improve the outcome of such procedures.”

Read the full study here and learn more about the CIRM grant here.

Stem Cell Agency Board Invests in Therapy Targeting Deadly Blood Cancers

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Dr. Ezra Cohen, photo courtesy UCSD

Hematologic malignancies are cancers that affect the blood, bone marrow and lymph nodes and include different forms of leukemia and lymphoma. Current treatments can be effective, but in those patients that do not respond, there are few treatment options. Today, the governing Board of the California Institute for Regenerative Medicine (CIRM) approved investing $4.1 million in a therapy aimed at helping patients who have failed standard therapy.

Dr. Ezra Cohen, at the University of California San Diego, and Oncternal Therapeutics are targeting a protein called ROR1 that is found in B cell malignancies, such as leukemias and lymphomas, and solid tumors such as breast, lung and colon. They are using a molecule called a chimeric antigen receptor (CAR) that can enable a patient’s own T cells, an important part of the immune system, to target and kill their cancer cells. These cells are derived from a related approach with an antibody therapy that targets ROR1-binding medication called Cirmtuzumab, also created with CIRM support. This CAR-T product is designed to recognize and kill cancer stem cells that express ROR1.

This is a late-stage preclinical project so the goal is to show they can produce enough high-quality cells to treat patients, as well as complete other regulatory measures needed for them to apply to the US Food and Drug Administration (FDA) for permission to test the therapy in a clinical trial in people.

If given the go-ahead by the FDA the therapy will target patients with chronic lymphocytic leukemia (CLL), mantle cell lymphoma (MCL) and acute lymphoblastic leukemia (ALL).  

“CAR-T cell therapies represent a transformational advance in the treatment of hematologic malignancies,” says Dr. Maria T. Millan, CIRM’s President and CEO. “This approach addresses the need to develop new therapies for patients whose cancers are resistant to standard chemotherapies, who have few therapeutic options and a very poor chance or recovery.”

Some good news for people with dodgy knees

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Graphic contrasting a healthy knee with one that has osteoarthritis

About 10% of Americans suffer from knee osteoarthritis, a painful condition that can really impair mobility and quality of life. It’s often caused by an injury to cartilage, say when you were playing sports in high school or college, and over time it continues to degenerate and ultimately results in the  loss of both cartilage and bone in the joint.

Current treatments involve either medication to control the pain or surgery. Medication works up to a point, but as the condition worsens it loses effectiveness.  Knee replacement surgery can be effective, but is a serious, complicated procedure with a long recovery time.  That’s why the governing Board of the California Institute for Regenerative Medicine (CIRM) voted to invest almost $6 million in an innovative stem cell therapy approach to helping restore articular cartilage in the knee.

Dr. Frank Petrigliano, Chief of the Epstein Family Center for Sports Medicine at Keck Medicine of the University of Southern California (USC), is using pluripotent stem cells to create chondrocytes (the cells responsible for cartilage formation) and then seeding those onto a scaffold. The scaffold is then surgically implanted at the site of damage in the knee. Based on scientific data, the seeded scaffold has the potential to regenerate the damaged cartilage, thus decreasing the likelihood of progression to knee osteoarthritis.  In contrast to current methods, this new treatment could be an off-the-shelf approach that would be less costly, easier to administer, and might also reduce the likelihood of progression to osteoarthritis.

This is a late-stage pre-clinical program. The goals are to manufacture clinical grade product, carry out extensive studies to demonstrate safety of the approach, and then file an IND application with the FDA, requesting permission to test the product in a clinical trial in people.

“Damage to the cartilage in our knees can have a big impact on quality of life,” says Dr. Maria T. Millan, MD, President and CEO of CIRM. “It doesn’t just cause pain, it also creates problems carrying out simple, everyday activities such as walking, climbing stairs, bending, squatting and kneeling. Developing a way to repair or replace the damaged cartilage to prevent progression to knee osteoarthritis could make a major difference in the lives of millions of Americans. This program is a continuation of earlier stage work funded by CIRM at the Basic Biology and Translational stages, illustrating how CIRM supports scientific programs from early stages toward the clinic.”

Looking back and looking forward: good news for two CIRM-supported studies

Dr. Rosa Bacchetta on the right with Brian Lookofsky (left) and Taylor Lookofsky after CIRM funded Dr. Bacchetta’s work in October 2019. Taylor has IPEX syndrome

It’s always lovely to end the week on a bright note and that’s certainly the case this week, thanks to some encouraging news about CIRM-funded research targeting blood disorders that affect the immune system.

Stanford’s Dr. Rosa Bacchetta and her team learned that their proposed therapy for IPEX Syndrome had been given the go-ahead by the Food and Drug Administration (FDA) to test it in people in a Phase 1 clinical trial.

IPEX Syndrome (it’s more formal and tongue twisting name is Immune dysregulation Polyendocrinopathy Enteropathy X-linked syndrome) is a life-threatening disorder that affects children. It’s caused by a mutation in the FOXP3 gene. Immune cells called regulatory T Cells normally function to protect tissues from damage but in patients with IPEX syndrome, lack of functional Tregs render the body’s own tissues and organs to autoimmune attack that could be fatal in early childhood. 

Current treatment options include a bone marrow transplant which is limited by available donors and graft versus host disease and immune suppressive drugs that are only partially effective. Dr. Rosa Bacchetta and her team at Stanford will use gene therapy to insert a normal version of the FOXP3 gene into the patient’s own T Cells to restore the normal function of regulatory T Cells.

This approach has already been accorded an orphan drug and rare pediatric disease designation by the FDA (we blogged about it last year)

Orphan drug designation is a special status given by the Food and Drug Administration (FDA) for potential treatments of rare diseases that affect fewer than 200,000 in the U.S. This type of status can significantly help advance treatments for rare diseases by providing financial incentives in the form of tax credits towards the cost of clinical trials and prescription drug user fee waivers.

Under the FDA’s rare pediatric disease designation program, the FDA may grant priority review to Dr. Bacchetta if this treatment eventually receives FDA approval. The FDA defines a rare pediatric disease as a serious or life-threatening disease in which the serious or life-threatening manifestations primarily affect individuals aged from birth to 18 years and affects fewer than 200,000 people in the U.S.

Congratulations to the team and we wish them luck as they begin the trial.

Dr. Donald Kohn, Photo courtesy UCLA

Someone who needs no introduction to regular readers of this blog is UCLA’s Dr. Don Kohn. A recent study in the New England Journal of Medicine highlighted how his work in developing a treatment for severe combined immune deficiency (SCID) has helped save the lives of dozens of children.

Now a new study in the journal Blood shows that those benefits are long-lasting, with 90% of patients who received the treatment eight to 11 years ago still disease-free.

In a news release Dr. Kohn said: “What we saw in the first few years was that this therapy worked, and now we’re able to say that it not only works, but it works for more than 10 years. We hope someday we’ll be able to say that these results last for 80 years.”

Ten children received the treatment between 2009 and 2012. Nine were babies or very young children, one was 15 years old at the time. That teenager was the only one who didn’t see their immune system restored. Dr. Kohn says this suggests that the therapy is most effective in younger children.

Dr. Kohn has since modified the approach his team uses and has seen even more impressive and, we hope, equally long-lasting results.

Them bones them bones them dry bones – and how to help repair them

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Broken bones

People say that with age comes wisdom, kindness and confidence. What they usually don’t say is that it also comes with aches and pains and problems we didn’t have when we were younger. For example, as we get older our bones get thinner and more likely to break and less likely to heal properly.

That’s a depressing opening paragraph isn’t it. But don’t worry, things get better from here because new research from Germany has found clues as to what causes our bones to become more brittle, and what we can do to try and stop that.

Researchers at the Max Planck Institute for Biology of Ageing and CECAD Cluster of Excellence for Ageing Research at the University of Cologne have identified changes in stem cells from our bone marrow that seem to play a key role in bones getting weaker as we age.

To explain this we’re going to have to go into the science a little, so bear with me. One of the issues the researchers focused on is the role of epigenetics, this is genetic information that doesn’t change the genes themselves but does change their activity. Think of it like a light switch. The switch doesn’t change the bulb, but it does control when it’s on and when it’s off. So this team looked at the epigenome of MSCs, the stem cells found in the bone marrow. These cells play a key role in the creation of cartilage, bone and fat cells.

In a news release, Dr. Andromachi Pouikli, one of the lead researchers in the study, says these MSCs don’t function as well as we get older.

“We wanted to know why these stem cells produce less material for the development and maintenance of bones as we age, causing more and more fat to accumulate in the bone marrow. To do this, we compared the epigenome of stem cells from young and old mice. We could see that the epigenome changes significantly with age. Genes that are important for bone production are particularly affected.”

So, they took some stem cells from the bone marrow of mice and tested them with a solution of sodium acetate. Now sodium acetate has a lot of uses, including being used in heating pads, hand warmers and as a food seasoning, but in this case the solution was able to make it easier for enzymes to get access to genes and boost their activity.

“This treatment impressively caused the epigenome to rejuvenate, improving stem cell activity and leading to higher production of bone cells,” Pouikli said.

So far so good. But does this work the same way in people? Maybe so. The team analyzed MSCs from people who had undergone hip surgery and found that they showed the same kind of age-related changes as the cells from mice.

Clearly there’s a lot more work to do before we can even think about using this finding as a solution to aging bones. But it’s an encouraging start.

The study is published in the journal Nature Aging.

A personal reason to develop a better gene therapy

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Credit : Allison Dougherty, Broad Communications

For Sharif Tabebordbar, finding a gene therapy for genetic muscle wasting diseases was personal. When he was a teenager, his father was diagnosed with a rare genetic muscle disease that eventually left him unable to walk.

In an interview with the Broad Institute at MIT he said: “I watched my dad get worse and worse each day. It was a huge challenge to do things together as a family – genetic disease is a burden on not only patients but families. I thought: This is very unfair to patients and there’s got to be a way to fix this. That’s been my motivation during the 10 years that I’ve been working in the field of gene therapy.”

That commitment now seems to be paying off. In a study published in the journal Cell, Tabebordar and his team at MIT and Harvard showed how they have developed a new, safer and easier way to deliver genes to help repair wasting muscles.   

In earlier treatments targeting genetic muscle diseases, researchers used a virus to help deliver the gene that would correct the problem. However, to be effective they had to use high doses of the gene-carrying virus to ensure it reached as many muscles throughout the body as possible. But this meant that more of the payload often ended up in the liver and that led to severe side effects in some patients, even a few deaths.

The usual delivery method of these gene-correcting therapies is something called an adeno-associated virus (AAV), so Dr. Tabebordar set out to develop a new kind of AAV, one that would be safer for patients and more effective at tackling the muscle wasting.

They started by taking an adeno-associated virus called AAV9 and then set out about tweaking its capsid – that’s the outer shell that helps protect the virus and allows it to attach to another cell and penetrate it to deliver the corrected gene. They called this new viral vector MyoAAV and in tests it quickly showed it had an enhanced ability to deliver genes into cells.

The team showed that it not only was around 10 times more efficient at reaching muscle than other AAVs, but that it also reduces the amount that reaches the liver. This meant that MyoAAV could achieve impressive results in doses up to 250 times lower than those previously used.

In animal studies MyoAAV showed encouraging results in diseases like Duchenne Muscular Dystrophy and X-linked myotubular myopathy. Dr. Amy Wagers, a co-senior author of the study, says they are hopeful it will be equally effective in people.

“All of these results demonstrate the broad applicability of the MyoAAV vectors for delivery to muscle. These vectors work in different disease models and across different ages, strains and species, which demonstrates the robustness of this family of AAVs. We have an enormous amount of information about this class of vectors from which the field can launch many exciting new studies.”

A rare chance to help those in need

Recently the CIRM Board voted to support the creation of a Rare Disease Advisory Council (RDAC) in California. An RDAC is an advisory body providing a platform for the rare community to have a stronger voice in state government. They address the needs of rare patients and families by giving stakeholders an opportunity to make recommendations to state leaders on critical issues including the need for increased awareness, diagnostic tools and access to affordable treatments and cures.  

California is now in the process of creating an RDAC but, as a recent article in STAT highlighted, we are far from the only one.

Guadalupe Hayes-Mota

21 states give rare disease patients a seat at the table. The other 29 need to follow suit
By Guadalupe Hayes-Mota Originally published by STAT on July 26, 2021

A powerful movement is taking shape in the U.S. rare disease community that could transform the lives of millions of people. That’s right — millions. Even though a single rare disease may affect only a few individuals, there are several thousand of these problematic diseases that are difficult to identify and treat.

Since 2015, 21 U.S. states have passed legislation to create Rare Disease Advisory Councils that provide platforms for patients and family members to communicate with experts, policymakers, and the broader public. It’s critical to seize this hopeful moment because the needs of so many people living with rare diseases go unaddressed.

I know because I’m one of them.

I was born and raised in a small town in Mexico and diagnosed at birth with hemophilia, a rare genetic disease that prevents the blood from clotting after trauma or injury. While treatment existed in other parts of the world, I had only limited access to it, forcing me to live an isolated childhood indoors, protected and isolated from the world.

When my appendix burst at age 12, I underwent emergency surgery, followed by a desperate eight-hour ambulance ride to a hospital in another town in search of better medication to stop the bleeding. Doctors told my parents I was unlikely to survive, but against all odds I did — after clinically dying twice in the operating room. I am one of the few lucky people with my condition to have survived severe bleeding events without treatment.

After this traumatic incident, my family moved to a small town in California’s Mojave Desert. Navigating the health care system as an immigrant and not knowing the language was complicated. Accessing treatment and services for my disease was almost impossible at first. The nearest specialist was 90 minutes away. Thankfully, with help from the hemophilia association chapter in our area, I gained access to care and treatment.

Read the complete article here.

Paving the Way

When someone scores a goal in soccer all the attention is lavished on them. Fans chant their name, their teammates pile on top in celebration, their agent starts calling sponsors asking for more money. But there’s often someone else deserving of praise too, that’s the player who provided the assist to make the goal possible in the first place. With that analogy in mind, CIRM just provided a very big assist for a very big goal.

The goal was scored by Jasper Therapeutics. They have just announced data from their Phase 1 clinical trial treating people with Myelodysplastic syndromes (MDS). This is a group of disorders in which immature blood-forming cells in the bone marrow become abnormal and leads to low numbers of normal blood cells, especially red blood cells. In about one in three patients, MDS can progress to acute myeloid leukemia (AML), a rapidly progressing cancer of the bone marrow cells.

The most effective way to treat, and even cure, MDS/AML is with a blood stem cell transplant, but this is often difficult for older patients, because it involves the use of toxic chemotherapy to destroy their existing bone marrow blood stem cells, to make room for the new, healthy ones. Even with a transplant there is often a high rate of relapse, because it’s hard for chemotherapy to kill all the cancer cells.

Jasper has developed a therapy, JSP191, which is a monoclonal antibody, to address this issue. JSP191 helps supplement the current treatment regimen by clearing all the remaining abnormal cells from the bone marrow and preventing relapse. In addition it also means the patients gets smaller doses of chemotherapy with lower levels of toxicity. In this Phase 1 study six patients, between the ages of 65 and 74, were given JSP191 – in combination with low-dose radiation and chemotherapy – prior to getting their transplant. The patients were followed-up at 90 days and five of the six had no detectable levels of MDS/AML, and the sixth patient had reduced levels. None of the patients experienced serious side effects.

Clearly that’s really encouraging news. And while CIRM didn’t fund this clinical trial, it wouldn’t have happened without us paving the way for this research. That’s where the notion of the assist comes in.

CIRM support led to the development of the JSP191 technology at Stanford. Our CIRM funds were used in the preclinical studies that form the scientific basis for using JSP191 in an MDS/AML setting.

Not only that, but this same technique was also used by Stanford’s Dr. Judy Shizuru in a clinical trial for children born with a form of severe combined immunodeficiency, a rare but fatal immune disorder in children. A clinical trial that CIRM funded.

It’s a reminder that therapies developed with one condition in mind can often be adapted to help treat other similar conditions. Jasper is doing just that. It hopes to start clinical trials this year using JSP191 for people getting blood stem cell transplants for severe autoimmune disease, sickle cell disease and Fanconi anemia.

Unlocking a key behind why our bones get weaker as we age

Magnified image of a bone with osteoporosis. Photo Courtesy Sciencephoto.com

Getting older brings with it a mixed bag of items. If you are lucky you can get wiser. If you are not so lucky you can get osteoporosis. But while scientists don’t know how to make you wiser, they have gained some new insights into what makes bones weak and so they might be able to help with the osteoporosis.

Around 200 million people worldwide suffer from osteoporosis, a disease that causes bones to become so brittle that in extreme cases even coughing can lead to a fracture.

Scientists have known for some time that the cells that form the building blocks of our skeletons are found in the bone marrow. They are called mesenchymal stem cells (MSCs) and they have the ability to turn into a number of different kinds of cells, including bone or fat. The keys to deciding which direction the MSCs take are things called epigenetic factors, these basically control which genes are switched on or off and in what order. Now researchers from the UCLA School of Dentistry have identified an enzyme that plays a critical role in that process.

The team found that when the enzyme KDM4B is missing in MSCs those cells are more likely to become fat cells rather than bone cells. Over time that leads to weaker bones and more fractures.

In a news release Dr. Cun-Yu Wang, the lead researcher, said: “We know that bone loss comes with age, but the mechanisms behind extreme cases such as osteoporosis have, up until recently, been very vague.”

To see if they were on the right track the team created a mouse model that lacked KDM4B. Just as they predicted the MSCs in the mouse created more fat than bone, leading to weaker skeletons.

They also looked at mice who were placed on a high fat diet – something known to increase bone loss and weaker bones in people – and found that the diet seemed to reduce KDM4B which in turn produced weaker bones.

In the news release Dr. Paul Krebsbach, Dean of the UCLA School of Dentistry, said the implications for the research are enormous. “The work of Dr. Wang, his lab members and collaborators provides new molecular insight into the changes associated with skeletal aging. These findings are an important step towards what may lead to more effective treatment for the millions of people who suffer from bone loss and osteoporosis.”

The study is published in the journal Cell Stem Cell.

Surviving with Joy

Dr. Tippi MacKenzie (left) of UCSF Benioff Children’s Hospital San Francisco, visits with newborn Elianna and parents Nichelle Obar and Chris Constantino. Photo by Noah Berger

Alpha thalassemia major is, by any stretch of the imagination, a dreadful, heart breaker of a disease. It’s caused by four missing or mutated genes and it almost always leads to a fetus dying before delivery or shortly after birth. Treatments are limited and in the past many parents were told that all they can do is prepare for the worst.

Now, however, there is new hope with new approaches, including one supported by CIRM, helping keep these children alive and giving them a chance at a normal life.

Thalassemias are a group of blood disorders that affect the way the body makes hemoglobin, which helps in carrying oxygen throughout the body. In alpha thalassemia major it’s the lack of alpha globin, a key part of hemoglobin, that causes the problem. Current treatment requires in blood transfusions to the fetus while it is still in the womb, and monthly blood transfusions for life after delivery, or a bone marrow transplant if a suitable donor is identified.

A clinical trial run by University of California San Francisco’s Dr. Tippi MacKenzie – funded by CIRM – is using a slightly different approach. The team takes stem cells from the mother’s bone marrow and then infuses them into the fetus. If accepted by the baby’s bone marrow, these stem cells can then mature into healthy blood cells. The hope is that one day this method will enable children to be born with a healthy blood supply and not need regular transfusions.

Treating these babies, saving their lives, is the focus of a short film from UCSF called “Surviving with Joy”. It’s a testament to the power of medicine, and the courage and resilience of parents who never stopped looking for a way to help their child.

Tissues are optional but advised.