Marissa Cors has lived with Sickle Cell Disease (SCD) for more than 40 years. The co-founder of The Sickle Cell Experience Live, an online platform designed to bring more awareness to Sickle Cell Disease around the world, says it’s hard, knowing that at any moment you may have to put your life on hold to cope with another attack of excruciating pain.
“It is incredibly frustrating to have a disease that is constantly disrupting and interfering with your life. The daily pain and fatigue make it difficult to have a normal life. You may be experiencing manageable pain one minute and then a crisis will hit – knocking you to the ground with horrible pain and requiring pain management and hospitalization. It makes going to school or having a job or even a normal adult relationship near impossible.”
SCD is an inherited disease caused by a single gene mutation resulting in abnormal hemoglobin, which causes red blood cells to ‘sickle’ in shape. Sickling of red blood cells clogs blood vessels and leads to progressive organ damage, pain crises, reduced quality of life, and early death.
The disease affects around 100,000 Americans, mostly Black Americans but also members of the Latinx community. Marissa says coping with it is more than just a medical struggle. “Born into the cycle of fatigue, pain and fear. Depending on a healthcare system filled with institutionalized bias and racism. It is a life that is difficult on all facets.”
CIRM is committed to trying find new treatments, and even a cure for SCD. That’s why the CIRM Board recently awarded $8,333,581 to Dr. David Williams at Boston Children’s Hospital to conduct a gene therapy clinical trial for sickle cell disease. This is the second project that is part of an agreement between CIRM and the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health, to co-fund cell and gene therapy programs under the NHLBI’s “Cure Sickle Cell” Initiative. The goal of this agreement is to markedly accelerate clinical development of cell and gene therapies to cure SCD.
In recent years we have made impressive strides in developing new approaches to treating sickle cell disease,” says Dr. Maria T. Millan, President & CEO of CIRM. “But we still have work to do. That’s why this partnership, this research is so important. It reflects our commitment to pushing ahead as fast as we can to find a treatment, a cure, that will help all the people battling the disease here in the U.S. and the estimated 20 million worldwide.”
The team will take a patient’s own blood stem cells and insert a novel engineered gene to silence abnormal hemoglobin and induce normal fetal hemoglobin expression. The modified blood stem cells will then be reintroduced back into the patient. The goal of this therapy is to aid in the production of normal shaped red blood cells, thereby reducing the severity of the disease.
For Marissa, anything that helps make life easier will be welcome not just for people with SCD but their families and the whole community. “A stem cell cure will end generations of guilt, suffering, pain and early death. It will give SCD families relief from the financial, emotional and spiritual burden of caring someone living with SCD. It will give all of us an opportunity to have a normal life. Go to school, go to work, live with confidence.”
At CIRM we are modest enough to know that we can’t do everything by ourselves. To succeed we need partners. And in UC Davis we have a terrific partner. The work they do in advancing stem cell research is exciting and really promising. But it’s not just the science that makes them so special. It’s also their compassion and commitment to caring for patients.
What follows is an excerpt from an article by Lisa Howard on the work they do at UC Davis. When you read it you’ll see why we are honored to be a part of this research.
Gene therapy research at UC Davis
UC Davis’ commitment to stem cell and gene therapy research dates back more than a decade.
In 2010, with major support from the California Institute for Regenerative Medicine (CIRM), UC Davis launched the UC Davis Institute for Regenerative Cures, which includes research facilities as well as a Good Manufacturing Practice (GMP) facility.
Led by Jan Nolta, a professor of cell biology and human anatomy and the director of the UC Davis Institute for Regenerative Cures, the new center leverages UC Davis’ network of expert researchers, facilities and equipment to establish a center of excellence aimed at developing lifelong cures for diseases.
Nolta began her career at the University of Southern California working with Donald B. Kohn on a cure for bubble baby disease, a condition in which babies are born without an immune system. The blood stem cell gene therapy has cured more than 50 babies to date.
Work at the UC Davis Gene Therapy Center targets disorders that potentially can be treated through gene replacement, editing or augmentation.
“The sectors that make up the core of our center stretch out across campus,” said Nolta. “We work with the MIND Institute a lot. We work with the bioengineering and genetics departments, and with the Cancer Center and the Center for Precision Medicine and Data Sciences.”
A recent UC Davis stem cell study shows a potential breakthrough for healing diabetic foot ulcers with a bioengineered scaffold made up of human mesenchymal stem cells (MSCs). Another recent study revealed that blocking an enzyme linked with inflammation enables stem cells to repair damaged heart tissue. A cell gene therapy study demonstrated restored enzyme activity in Tay-Sachs disease affected cells in humanized mouse models.
“Some promising and exciting research right now at the Gene Therapy Center comes from work with hematopoietic stem cells and with viral vector delivery,” said Nolta.
Hematopoietic stem cells give rise to other blood cells. A multi-institutional Phase I clinical trial using hematopoietic stem cells to treat HIV-lymphoma patients is currently underway at UC Davis.
“We are genetically engineering a patient’s own blood stem cells with genes that block HIV infection,” said Joseph Anderson, an associate professor in the UC Davis Department of Internal Medicine. The clinical trial is a collaboration with Mehrdad Abedi, the lead principal investigator.
“When the patients receive the modified stem cells, any new immune system cell, like T-cell or macrophage, that is derived from one of these stem cells, will contain the HIV-resistant genes and block further infection,” said Anderson.
He explained that an added benefit with the unique therapy is that it contains an additional gene that “tags” the stem cells. “We are able to purify the HIV-resistant cells prior to transplantation, thus enriching for a more protective cell population.
Kyle David Fink
Kyle David Fink, an assistant professor of neurology at UC Davis, is affiliated with the Stem Cell Program and Institute for Regenerative Cures. His lab is focused on leveraging institutional expertise to bring curative therapies to rare, genetically linked neurological disorders.
“We are developing novel therapeutics targeted to the underlying genetic condition for diseases such as CDKL5 deficiency disorder, Angelman, Jordan and Rett syndromes, and Juvenile Huntington’s disease,” said Fink.
The lab is developing therapies to target the underlying genetic condition using DNA-binding domains to modify gene expression in therapeutically relevant ways. They are also creating novel delivery platforms to allow these therapeutics to reach their intended target: the brain.
“The hope is that these highly innovative methods will speed up the progress of bringing therapies to these rare neurodegenerative disease communities,” said Fink.
Jasmine Carter, a graduate research assistant at the UC Davis Stem Cell Program, October 18, 2019. (AJ Cheline/UC Davis)
Developing potential lifetime cures
Among Nolta’s concerns is how expensive gene therapy treatments can be.
“Some of the therapies cost half a million dollars and that’s simply not available to everyone. If you are someone with no insurance or someone on Medicare, which reimburses about 65 percent, it’s harder for you to get these life-saving therapies,” said Nolta.
To help address that for cancer patients at UC Davis, Nolta has set up a team known as the “CAR T Team.”
Chimeric antigen receptor (CAR) T-cell therapy is a type of immunotherapy in which a patient’s own immune cells are reprogrammed to attack a specific protein found in cancer cells.
“We can develop our own homegrown CAR T-cells,” said Nolta. “We can use our own good manufacturing facility to genetically engineer treatments specifically for our UC Davis patients.”
Although safely developing stem cell treatments can be painfully slow for patients and their families hoping for cures, Nolta sees progress every day. She envisions a time when gene therapy treatments are no longer considered experimental and doctors will simply be able to prescribe them to their patients.
“And the beauty of the therapy is that it can work for the lifetime of a patient,” said Nolta.
Patient Advocates play an important role in everything we do at the stem cell agency, helping inform all the decisions we make. So it was gratifying to hear from one of our Advocates par excellence, Adrienne Shapiro, about her support for our Board’s decision to borrow $4.2 million from our Sickle Cell Cure fund to invest in rapid research for COVID-19. The money will be repaid but it’s clear from Adrienne’s email that she thinks the Board’s action is one that stands to benefit all of us.
Last Friday the CIRM Board voted to borrow $4.2 million dollars from the Sickle Cell Stem Cell Cure’s budget to fund Covid-19 research. The loan will be paid back at the end of the year from funds that are returned to the CIRM budget from projects that did not use them. At first I thought “that makes sense, if the money is not being used …” then I thought how wonderful it was that the SCD budget was there and could be used for Covid-19 research.
Wonderful because Covid-19 is a great threat to the SCD community. Sickle cell patients are at risk of dying from the virus as many have no spleens, are immune-compromised and suffer from weakened lung function due to damage from sickling red blood cells and low oxygen levels.
Wonderful because CIRM sponsored the first large clinical stem cell trials for a cure to SCD. Their funding and commitment to finding a universal cure for SCD opened what feels like a flood gate of research for a cure and new treatments.
Wonderful because it gives CIRM an opportunity to show the world what a government organization — that is committed to tackling complex medical problems — can accomplish using efficient, inclusive, responsible and agile methodologies.
I am eager to see what happens. We all hope that new treatments and even a cure will be found soon. If it does not come from CIRM funding we know that whatever is proven using these funds will help future researchers and patients.
After all: the SCD community is living proof that science done well leads to a world with less suffering
This year the most widely read blog was actually one we wrote back in 2018. It’s the transcript of a Facebook Live: “Ask the Stem Cell Team” event about strokes and stroke recovery. Because stroke is the third leading cause of death and disability in the US it’s probably no surprise this blog has lasting power. So many people are hoping that stem cells will help them recover from a stroke.
But of the blogs that we wrote and posted this year there’s a really interesting mix of topics.
The most read 2019 blog was about a potential breakthrough in the search for a treatment for type 1 diabetes (T1D). Two researchers at UC San Francisco, Dr. Matthias Hebrok and Dr. Gopika Nair developed a new method of replacing the insulin-producing cells in the pancreas that are destroyed by type 1 diabetes.
Dr. Hebrok described it as a big advance saying: “We can now generate insulin-producing cells that look and act a lot like the pancreatic beta cells you and I have in our bodies. This is a critical step towards our goal of creating cells that could be transplanted into patients with diabetes.”
It’s not too surprising a blog about type 1 diabetes was at the top. This condition affects around 1.25 million Americans, a huge audience for any potential breakthrough. However, the blog that was the second most read is the exact opposite. It is about a rare disease called cystinosis. How rare? Well, there are only around 500 children and young adults in the US, and just 2,000 worldwide diagnosed with this condition.
It might be rare but its impact is devastating. A genetic mutation means children with this condition lack the ability to clear an amino acid – cysteine – from their body. The buildup of cysteine leads to damage to the kidneys, eyes, liver, muscles, pancreas and brain.
UC San Diego researcher Dr. Stephanie Cherqui and her team are taking the patient’s own blood stem cells and, in the lab, genetically re-engineering them to correct the mutation, then returning the cells to the patient. It’s hoped this will create a new, healthy blood system free of the disease.
Dr. Cherqui says if it works, this could help not just people with cystinosis but a wide array of other disorders: “We were thrilled that the stem cells and gene therapy worked so well to prevent tissue degeneration in the mouse model of cystinosis. This discovery opened new perspectives in regenerative medicine and in the application to other genetic disorders. Our findings may deliver a completely new paradigm for the treatment of a wide assortment of diseases including kidney and other genetic disorders.”
The third most read blog was about another rare disease, but one that has been getting a lot of media attention this past year. Sickle cell disease affects around 100,000 Americans, mostly African Americans. In November the Food and Drug Administration (FDA) approved Oxbryta, a new therapy that reduces the likelihood of blood cells becoming sickle shaped and clumping together – causing blockages in blood vessels.
But our blog focused on a stem cell approach that aims to cure the disease altogether. In many ways the researchers in this story are using a very similar approach to the one Dr. Cherqui is using for cystinosis. Genetically correcting the mutation that causes the problem, creating a new, healthy blood system free of the sickle shaped blood cells.
Two other blogs deserve honorable mentions here as well. The first is the story of James O’Brien who lost the sight in his right eye when he was 18 years old and now, 25 years later, has had it restored thanks to stem cells.
The fifth most popular blog of the year was another one about type 1 diabetes. This piece focused on the news that the CIRM Board had awarded more than $11 million to Dr. Peter Stock at UC San Francisco for a clinical trial for T1D. His approach is transplanting donor pancreatic islets and parathyroid glands into patients, hoping this will restore the person’s ability to create their own insulin and control the disease.
2019 was certainly a busy year for CIRM. We are hoping that 2020 will prove equally busy and give us many new advances to write about. You will find them all here, on The Stem Cellar.
CIRM funds research trying to solve the Alzheimer’s puzzle
In science, there are a lot of terms that could easily mystify people without a research background; “translational” is not one of them. Translational research simply means to take findings from basic research and advance them into something that is ready to be tested in people in a clinical trial.
Yesterday our Governing Board approved $15 million in funding for four projects as part of our Translational Awards program, giving them the funding and support that we hope will ultimately result in them being tested in people.
Those projects use a variety of different approaches in tackling some very different diseases. For example, researchers at the Gladstone Institutes in San Francisco received $5.9 million to develop a new way to help the more than five million Americans battling Alzheimer’s disease. They want to generate brain cells to replace those damaged by Alzheimer’s, using induced pluripotent stem cells (iPSCs) – an adult cell that has been changed or reprogrammed so that it can then be changed into virtually any other cell in the body.
CIRM’s mission is to accelerate stem cell treatments to patients with unmet medical needs and Alzheimer’s – which has no cure and no effective long-term treatments – clearly represents an unmet medical need.
Another project approved by the Board is run by a team at Children’s Hospital Oakland Research Institute (CHORI). They got almost $4.5 million for their research helping people with sickle cell anemia, an inherited blood disorder that causes intense pain, and can result in strokes and organ damage. Sickle cell affects around 100,000 people in the US, mostly African Americans.
The CHORI team wants to use a new gene-editing tool called CRISPR-Cas9 to develop a method of editing the defective gene that causes Sickle Cell, creating a healthy, sickle-free blood supply for patients.
Right now, the only effective long-term treatment for sickle cell disease is a bone marrow transplant, but that requires a patient to have a matched donor – something that is hard to find. Even with a perfect donor the procedure can be risky, carrying with it potentially life-threatening complications. Using the patient’s own blood stem cells to create a therapy would remove those complications and even make it possible to talk about curing the disease.
While damaged cartilage isn’t life-threatening it does have huge quality of life implications for millions of people. Untreated cartilage damage can, over time lead to the degeneration of the joint, arthritis and chronic pain. Researchers at the University of Southern California (USC) were awarded $2.5 million to develop an off-the-shelf stem cell product that could be used to repair the damage.
The fourth and final award ($2.09 million) went to Ankasa Regenerative Therapeutics, which hopes to create a stem cell therapy for osteonecrosis. This is a painful, progressive disease caused by insufficient blood flow to the bones. Eventually the bones start to rot and die.
As Jonathan Thomas, Chair of the CIRM Board, said in a news release, we are hoping this is just the next step for these programs on their way to helping patients:
“These Translational Awards highlight our goal of creating a pipeline of projects, moving through different stages of research with an ultimate goal of a successful treatment. We are hopeful these projects will be able to use our newly created Stem Cell Center to speed up their progress and pave the way for approval by the FDA for a clinical trial in the next few years.”
Battling a deadly disease like cancer or Alzheimer’s is difficult; but battling a rare and deadly disease is doubly so. At least with common diseases there is a lot of research seeking to develop new treatments. With rare diseases there is often very little research, and so there are fewer options for treatment. Even just getting a diagnosis can be hard because most doctors may never have heard about, let alone seen, a case of a disease that only affects a few thousand individuals.
That’s why the last day of February, every year, has been designated Rare Disease Day. It’s a time to raise awareness amongst the public, researchers, health professionals and policy makers about the impact these diseases have on the lives of those affected by them. This means not just the individual with the problem, but their family and friends too.
There are nearly 7,000 diseases in the U.S. that are considered rare, meaning they affect fewer than 200,000 people at any given time.
No numbers no money
The reason why so many of these diseases have so few treatment options is obvious. With diseases that affect large numbers of people a new treatment or cure stands to make the company behind it a lot of money. With diseases that affect very small numbers of people the chances of seeing any return on investment are equally small.
Fortunately at CIRM we don’t have to worry about making a profit, all we are concerned with is accelerating stem cell treatments to patients with unmet medical needs. And in the case of people with rare diseases, those needs are almost invariably unmet.
As in everything we do our involvement is not just about funding research – important as that is – it’s also about engaging with the people most affected by these diseases, the patient advocate community. Patient advocates help us in several ways:
Collaborating with us and other key stakeholders to try and change the way the Food and Drug Administration (FDA) works. Our goal is to create an easier and faster, but no less safe, method of approving the most promising stem cell therapies for clinical trial. With so few available treatments for rare diseases having a smoother route to a clinical trial will benefit these communities.
Spreading the word to researchers and companies about CIRM 2.0, our new, faster and more streamlined funding opportunities to help us move the most promising therapies along as fast as possible. The good news is that this means anyone, anywhere can apply for funding. We don’t care how many people are affected by a disease, we only care about the quality of the proposed research project that could help them.
Recruiting Patient Advocates to our Clinical Advisory Panels (CAPs), teams that we assign to each project in a clinical trial to help guide and inform the researchers at every stage of their work. This not only gives each project the best possible chance of succeeding but it also helps the team stay focused on the mission, of saving, and changing, people’s lives.
Helping us recruit patients for clinical trials. The inability to recruit and retain enough patients to meet a project’s enrollment requirements is one of the biggest reasons many clinical trials fail. This is particularly problematic for rare diseases. By using Patient Advocates to increase our ability to enroll and retain patients we will increase the likelihood a clinical trial is able to succeed.
Organizing to fight back
There are some great organizations supporting and advocating on behalf of families affected by rare diseases, such as the EveryLife Foundation and the National Organization for Rare Diseases (NORD). They are working hard to raise awareness about these diseases, to get funding to do research, and to clear away some of the regulatory hurdles researchers face in being able to move the most promising therapies out of the lab and into clinical trials where they can be tested on people.
For the individuals and families affected by conditions like beta thalassemia and muscular dystrophy – potentially fatal genetic disorders – every day is Rare Disease Day. They live with the reality of these problems every single day. That’s why we are committed to working hard every single day, to find a treatment that can help them and their loved ones.
For the nearly 1,000 babies born each year in the United States with sickle cell disease, a painful and arduous road awaits them. The only cure is to find a bone marrow donor—an exceedingly rare proposition. Instead, the standard treatment for this inherited blood disorder is regular blood transfusions, with repeated hospitalizations to deal with complications of the disease. And even then, life expectancy is less than 40 years old.
In Sickle Cell Disease, the misshapen red blood cells cause painful blood clots and a host of other complications.
But now, scientists at UCLA are offering up a potentially superior alternative: a new method of gene therapy that can correct the genetic mutation that causes sickle cell disease—and thus help the body on its way to generate normal, healthy blood cells for the rest of the patient’s life. The study, funded in part by CIRM and reported in the journal Blood, offers a great alternative to developing a functional cure for sickle cell disease. The UCLA team is about to begin a clinical trial with another gene therapy method, so they—and their patients—will now have two shots on goal in their effort to cure the disease.
Though sickle cell disease causes dangerous changes to a patient’s entire blood supply, it is caused by one single genetic mutation in the beta-globin gene—altering the shape of the red blood cells from round and soft to pointed and hard, thus resembling a ‘sickle’ shape for which the disease is named. But the UCLA team, led by Donald Kohn, has now developed two methods that can correct the harmful mutation. As he explained in a UCLA news release about the newest technique:
“[These results] suggest the future direction for treating genetic diseases will be by correcting the specific mutation in a patient’s genetic code. Since sickle cell disease was the first human genetic disease where we understood the fundamental gene defect, and since everyone with sickle cell has the exact same mutation in the beta-globin gene, it is a great target for this gene correction method.”
The latest gene correction technique used by the team uses special enzymes, called zinc-finger nucleases, to literally cut out and remove the harmful mutation, replacing it with a corrected version. Here, Kohn and his team collected bone marrow stem cells from individuals with sickle cell disease. These bone marrow stem cells would normally give rise to sickle-shaped red blood cells. But in this study, the team zapped them with the zinc-finger nucleases in order to correct the mutation.
Then, the researchers implanted these corrected cells into laboratory mice. Much to their amazement, the implanted cells began to replicate—into normal, healthy red blood cells.
Kohn and his team worked with Sangamo BioSciences, Inc. to design the zinc-finger nucleases that specifically targeted and cut the sickle-cell mutation. The next steps will involve improving the efficiency and safest of this method in pre-clinical animal models, before moving into clinical trials.
“This is a promising first step in showing that gene correction has the potential to help patients with sickle cell disease,” said UCLA graduate student Megan Hoban, the study’s first author. “The study data provide the foundational evidence that the method is viable.”
This isn’t the first disease for which Kohn’s team has made significant strides in gene therapy to cure blood disorders. Just last year, the team announced a promising clinical trial to cure Severe Combined Immunodeficiency Syndrome, also known as SCID or “Bubble Baby Disease,” by correcting the genetic mutation that causes it.
While this current study still requires more research before moving into clinical trials, Kohn and his team announced last month that their other gene therapy method, also funded by CIRM, has been approved to start clinical trials. Kohn argues that it’s vital to explore all promising treatment options for this devastating condition:
“Finding varied ways to conduct stem cell gene therapies is important because not every treatment will work for every patient. Both methods could end up being viable approaches to providing one-time, lasting treatments for sickle cell disease and could also be applied to the treatment of a large number of other genetic diseases.”
Find Out More:
Read first-hand about Sickle Cell Disease in our Stories of Hope series.
Watch Donald Kohn speak to CIRM’s governing Board about his research.
In 2004, when 59 percent of California voters approved the creation of CIRM, our state embarked on an unprecedented experiment: providing concentrated funding to a new, promising area of research. The goal: accelerate the process of getting therapies to patients, especially those with unmet medical needs.
Having 10 potential treatments expected to be approved for clinical trials by the end of this year is no small feat. Indeed, it is viewed by many in the industry as a clear acceleration of the normal pace of discovery. Here are our first 10 treatments to be approved for testing in patients.
HIV/AIDS. The company Calimmune is genetically modifying patients’ own blood-forming stem cells so that they can produce immune cells—the ones normally destroyed by the virus—that cannot be infected by the virus. It is hoped this will allow the patients to clear their systems of the virus, effectively curing the disease.
Spinal cord injury patient advocate Katie Sharify is optimistic about the clinical trial led by Asterias Biotherapeutics.
Spinal Cord Injury. The company Asterias Biotherapeutics uses cells derived from embryonic stem cells to heal the spinal cord at the site of injury. They mature the stem cells into cells called oligodendrocyte precursor cells that are injected at the site of injury where it is hoped they can repair the insulating layer, called myelin, that normally protects the nerves in the spinal cord.
Heart Disease. The company Capricor is using donor cells derived from heart stem cells to treat patients developing heart failure after a heart attack. In early studies the cells appear to reduce scar tissue, promote blood vessel growth and improve heart function.
Solid Tumors. A team at the University of California, Los Angeles, has developed a drug that seeks out and destroys cancer stem cells, which are considered by many to be the reason cancers resist treatment and recur. It is believed that eliminating the cancer stem cells may lead to long-term cures.
Leukemia. A team at the University of California, San Diego, is using a protein called an antibody to target cancer stem cells. The antibody senses and attaches to a protein on the surface of cancer stem cells. That disables the protein, which slows the growth of the leukemia and makes it more vulnerable to other anti-cancer drugs.
Sickle Cell Anemia. A team at the University of California, Los Angeles, is genetically modifying a patient’s own blood stem cells so they will produce a correct version of hemoglobin, the oxygen carrying protein that is mutated in these patients, which causes an abnormal sickle-like shape to the red blood cells. These misshapen cells lead to dangerous blood clots and debilitating pain The genetically modified stem cells will be given back to the patient to create a new sickle cell-free blood supply.
Solid Tumors. A team at Stanford University is using a molecule known as an antibody to target cancer stem cells. This antibody can recognize a protein the cancer stem cells carry on their cell surface. The cancer cells use that protein to evade the component of our immune system that routinely destroys tumors. By disabling this protein the team hopes to empower the body’s own immune system to attack and destroy the cancer stem cells.
Diabetes. The company Viacyte is growing cells in a permeable pouch that when implanted under the skin can sense blood sugar and produce the levels of insulin needed to eliminate the symptoms of diabetes. They start with embryonic stem cells, mature them part way to becoming pancreas tissues and insert them into the permeable pouch. When transplanted in the patient, the cells fully develop into the cells needed for proper metabolism of sugar and restore it to a healthy level.
HIV/AIDS. A team at The City of Hope is genetically modifying patients’ own blood-forming stem cells so that they can produce immune cells—the ones normally destroyed by the virus—that cannot be infected by the virus. It is hoped this will allow the patients to clear their systems of the virus, effectively curing the disease
Blindness. A team at the University of Southern California is using cells derived from embryonic stem cell and a scaffold to replace cells damaged in Age-related Macular Degeneration (AMD), the leading cause of blindness in the elderly. The therapy starts with embryonic stem cells that have been matured into a type of cell lost in AMD and places them on a single layer synthetic scaffold. This sheet of cells is inserted surgically into the back of the eye to replace the damaged cells that are needed to maintain healthy photoreceptors in the retina.
This week on The Stem Cellar we feature some of our most inspiring patients and patient advocates as they share, in their own words, their Stories of Hope.
Adrienne Shapiro pledged she would give her daughter Marissa the best possible life she could have—wearing herself out if necessary. Her baby girl had sickle cell disease, an inherited disorder in which the body’s oxygen-carrying red blood cells become crescent shaped, sticky, rigid, and prone to clumping—blocking blood flow. Doctors warned Adrienne that Marissa might not live to see her first birthday. When Marissa achieved that milestone, they moved the grim prognosis back a year, and then another year, and then another.
Adrienne has lived through several generations of the inherited blood disease.
Adrienne worked tirelessly to help Marissa. “I was constantly asking questions,” Shapiro says. And for a long time, it worked.
However, things began to unravel for Marissa as she reached adulthood. A standard treatment for sickle cell disease—and the excruciating pain caused by blocked blood vessels—is regular blood transfusions. A transfusion floods the body with healthy, round red blood cells, lowering the proportion of the deformed, ‘sickle-shaped’ cells. But when she was 20, a poorly matched blood transfusion triggered a cascade of immune problems. Later, surgery to remove her gall bladder set off a string of complications and her kidneys shut down temporarily. After that, her immune system couldn’t take any more insults. Now, at age 36, she’s hypersensitive.
“She can’t be transfused. She can’t even have tape next to her skin without her body reacting,” Adrienne said.
Pain control is the newest and continuing nightmare. Adrienne tells harrowing stories of long waits in hospital emergency rooms while her daughter suffers, followed by maddening arguments with staff reluctant to provide enough drugs to control the intense pain when her daughter is finally admitted.
“When she was a kid, everyone wanted to make her feel good,” Adrienne says. “But when we moved from the pediatric side to the adult side, they treated her as a drug seeker and me as an enabler. It’s such a slap in the face.”
For Adrienne, the story is all too familiar. She is the third generation in her family with a sickle cell child. Another daughter, Casey Gibson, does not have the disease but carries the sickle cell mutation, meaning she could pass it to a child if the father also has the trait. One in 500 African Americans has sickle cell disease, as do 1 in 36,000 Hispanic people.
There is only one sure way to stop this story from repeating for generations to come, Adrienne says, and that’s research. She believes stem cell science will be the answer.
“I’ve been waiting for this science to get to the point where it had a bona fide cure, something that worked. Now we’re actually nearing clinical trials. It’s so close.”
In fact a CIRM-funded project led by Don Kohn, M.D. at UCLA aims to start trials in 2014. Kohn and his team intend to remove bone marrow from the patient and fix the genetic defect in the blood-forming stem cells. Then those cells can be reintroduced into the patient to create a new, healthy blood system.
“Stem cells are our only hope,” Adrienne continues, “It’s my true belief that I’m going to be the last woman in my family to have a child with sickle cell disease. Marissa’s going to be the last child to suffer, and Casey is going to be the last one to fear. Stem cells are going to fix this for us and many other families.”
For those who suffer from the blood disorder sickle cell disease, there is really only one cure: a full bone marrow transplant followed by a lifetime of anti-rejection, immune-suppressing drugs. But now, researchers from the National Institutes of Health are testing an attractive alternative for the sickest patients.
Sickle cell disease gets its name from a single genetic change, or mutation, that alters the shape of one’s red blood cells.. Unlike the round cells that can pass easily through the body’s blood vessels, the sickle-shaped cells clump together, clogging up blood vessels. This leads to a lifetime of severe joint pain and, in many cases, organ damage and stroke. In this country it affects primarily African Americans.
Magnified blood sample of a patient with severe sickle cell disease.
The only cure is a bone marrow transplant, in which the patient’s own bone marrow is first depleted with chemotherapy, and replaced by the donor marrow. The patient then faces a lifetime of immunosuppressant, anti-rejection medication to prevent deadly rejection or graft-versus-host disease, a potentially fatal condition where the donor cells attack the recipient’s immune system.
But what if, instead of replacing the entirety of the patient’s bone marrow, doctors only replaced some of it? Would this mix of sickle and non-sickle-shaped cells be enough to reverse the symptoms? A clinical trial published today from the NIH research team in the Journal of the American Medical Association has some encouraging results.
“Typically, stem-cell recipients must take immunosuppressants all their lives. That the patients who discontinued this medication were able to do so safely points to the stability of the partial transplant regimen.”
In this study, the researchers performed partial bone marrow transplantations on 30 adults with severe sickle cell disease. After one year, they took 15 patients off the standard regimen of immunosuppressant drugs. And more than three years later, those 15 patients remain free from rejection.
These results are promising, in that a lifetime of immunosuppressants comes with its own set of negative side effects for the patient. According to the paper’s senior author Dr. John Tinsdale:
“Side effects caused by immunosuppressants can endanger patients already weakened by years of organ damage from sickle cell disease. Not having to permanently rely on this medication…means that even older patients and those with severe sickle cell disease may be able to reverse their condition.”
Indeed, the research team found that even a partial transplant—which resulted in a stable mix of both red blood cell types from donor and recipient – was sufficient to reverse the disease’s debilitating symptoms.
The results from this trial open the door to treating patients whose immune systems are already too weak—and are unable to tolerate the negative effects of a full stem cell transplant.
But even this half transplant has the risks associated with donor marrow. That is why CIRM is funding a team using a patient’s own stem cells and genetically modifying them to produce the correct version of the mutated protein. These self-transplants would be safer and open up the therapy to all patients regardless of their ability to find an immunologically matching donor. We expect a clinical trial with this approach to begin soon.