Blood stem cell expansion expands treatment options for cancer patients

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Image courtesy of the Stower’s Institute

Bone marrow transplants have been used for decades to treat various types of cancers such as leukemia and multiple myeloma, as well as other blood disorders such as anemia.

Our bone marrow is responsible for making hematopoietic stem cells (HSCs), which develop into mature blood cells, like white cells (which fight infection) and red cells (which carry oxygen throughout our body). In different types of blood disorders, blood cell production is either impaired or abnormal. In leukemia for example, the body produces abnormal white blood cells that survive better then outgrow the normal white cells, thus impairing the individual’s ability to fight infection. Bone marrow transplants, which involves replacing the diseased marrow with healthy marrow from a donor, can be incredibly effective for these types of disease. Survival from certain blood cancers increased from basically zero to around eighty-five percent after the advent of bone marrow transplant therapy.

While extremely effective when successful, bone marrow transplants do not work for everyone and finding a match can be difficult. For example, only 30% of patients are able to find a match in their families, because of the strict requirements that must be fulfilled be a bone marrow match. Stem cells from umbilical cord blood, on the other hand, are much more likely to match a patient, because of the generally less stringent requirements to be a match. The amount of cord blood (nearly two whole cords worth of blood) needed to satisfy an adult patient’s transplant requirements, however, are significant, and can be a limiting factor in the efficiency and effectiveness of this approach. New research from Lingheng Li’s lab at the Stower’s Institute for Medical Research at the University of Kansas has found a possible solution to this problem.

In a study published in Cell Research, Li’s group found a way to increase the number of adult stem cells isolated from cord blood, which could reduce the number of cords needed per treatment. By eliminating a protein called Ythdf2 in mice, they observed global expansion of HSCs. Normally, this protein is responsible for preventing expression of genes involved in promoting HSC expansion. Importantly, the researchers found that the HSC expansion stimulated by elimination of Ythdf2 did not lead to other abnormalities in the resulting HSCs and did not affect the ability of these HSCs to produce different types of blood stem cells down the road. Dr. Li believes that this type of approach can be applied to other types of stem cell treatments as well.

Dr. Joseph McGuirk, another professor at the University of Kansas who was not directly involved with this study, indicates the importance of this work:

“This work represents a path forward by demonstrating the ability to reliably expand adult stem cells from umbilical cord blood in the laboratory without terminally differentiating the cells into more mature and relatively short-lived blood cells. These findings represent a major advance in the field and have significant potential to improve the outcomes of thousands of children and adults who undergo umbilical cord blood transplantation every year.”

CIRM is funding work in this area too. We are supporting a late stage preclinical project with AngioCrine Biosciences which is using expanded cord blood stem cells. They hope to create an effective and, safe option for the treatment of debilitating blood diseases such as leukemia and lymphoma.

Fish umbrellas and human bone: protecting blood stem cells from the sun’s UV rays

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Most people probably do not question the fact that human blood stem cells – those that give rise to all the cells in our blood – live inside the marrow of our bones, called a stem cell “niche”. But it is pretty odd when you stop to think about it. I mean, it makes sense that the hard, calcium-rich structure of bones provide our bodies with a skeleton but why is it also responsible for making our blood?

This week, researchers at Harvard report in Nature that the answer may come down to protecting these precious cells from the DNA-damaging effects of UV radiation from the sun. They arrived at those insights by examining zebrafish which harbor blood stem cells, not in their bones, but in their kidneys. Fredrich Kapp, MD, the first author of the report, was trying to analyze blood stem cells in zebrafish under the microscope but noticed a layer of other cells on top of the kidney was obscuring his view.

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In a zebrafish larva (illustration above), a dark umbrella formed by pigmented cells (white arrows point to these black spots in box, left) in the kidney protects vulnerable stem cells from damaging UV light. Right image is a closeup of the box. Scale bars equal 100 micrometers (left) and 50 micrometers (right). Credit: F. Kapp et al./Nature 2018
Read more at: https://phys.org/news/2018-06-blood-cells-bones.html#jCp

That layer of cells turned out to be melanocytes which produce melanin a pigment that gives our skin color. Melanin also protects our skin cells from the sun’s UV radiation which damages our DNA and can cause genetic mutations. In a press release, Kapp recalled his moment of insight:

“The shape of the melanocytes above the kidney reminded me of a parasol, so I thought, do they provide UV protection to blood stem cells?”

To answer his question, he and his colleagues compared the effects of UV radiation on normal zebrafish versus mutant zebrafish lacking the layer of melanocytes. Confirming Kapp’s hypothesis, the fish missing the melanocyte layer had fewer blood stem cells. Simply turning the normal fish upside down and exposing them to the UV rays also depleted the blood stem cells.

And here’s where the story gets really cool. In studying frogs – animals closer to us on the evolutionary tree – they found that as the tadpole begins to grow legs, their blood stem cells migrate from the melanocyte-covered kidney cells to inside the bone marrow, an even better form of UV protection. Senior author Leonard Zon explained the importance of this finding:

“We now have evidence that sunlight is an evolutionary driver of the blood stem cell niche. As a hematologist and oncologist, I treat patients with blood diseases and cancers. Once we understand the niche better, we can make blood stem cell transplants much safer.”

 

 

CIRM funded study results in the first ever in utero stem cell transplant to treat alpha thalassemia

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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

Imagine being able to cure a genetic disorder before a baby is even born. Thanks to a CIRM funded study, what would have been a mere dream a couple of years ago has become a reality.

Drs. Tippi MacKenzie and Juan Gonzalez Velez of the University of California San Francisco (UCSF) have successfully treated alpha thalassemia in Elianna Constantino, using stem cells from her mother’s bone marrow. Alpha thalassemia is part of a group of blood disorders that impairs the body’s ability to produce hemoglobin, the molecule that is responsible for transporting oxygen throughout the body on red blood cells. Present in approximately 5% of the population, alpha thalassemia is particularly prevalent among individuals of Asian heritage. Treatment options for this disease are severely limited, generally requiring multiple rounds of blood transfusions or a bone marrow transplant which requires immunosuppressive therapy. Normally, fetuses die in the womb or the pregnancy is aborted because of the poor prognosis.

The revolutionary treatment pioneered at UCSF involved isolating blood stem cells (cells that are capable of turning into all blood cell types) from the mother’s bone marrow and injecting these cells into Elianna’s bloodstream via the umbilical vein. The doctors were able to observe the development of healthy blood cells in the baby’s blood stream, allowing for efficient oxygen transport throughout the baby’s body. Because the cells were transplanted at the fetal stage, a time when the immune system is not fully developed, there was low risk of rejection and the transplant occurred without aggressive immunosuppressive therapy.

The baby was born healthy earlier this year and has been allowed to return home. While it is still too early to tell how effective this treatment will be in the long term, it is very encouraging that both the mother and baby have endured the treatment thus far.

In a press release, Dr. MacKenzie states:

“Her healthy birth suggests that fetal therapy is a viable option to offer to families with this diagnosis.”

The in utero stem cell transplant was performed as part of a clinical trial conducted at the UCSF Benioff Children’s Hospitals in San Francisco and Oakland. The trial is currently enrolling 10 pregnant women to test the safety and effectiveness of this treatment over a wider population.

If successful, this type of treatment is particularly exciting because it could be expanded to other types of hereditary blood disorders such as sickle cell anemia and hemophilia.

 

 

 

Sonic Hedgehog provides pathway to fight blood cancers

Dr. Catriona Jamieson: Photo courtesy Moores Cancer Center, UCSD

Dr. Catriona Jamieson:
Photo courtesy Moores Cancer Center, UCSD

For a lot of people Sonic Hedgehog is a video game. But for stem cell researcher Dr. Catriona Jamieson it is a signaling pathway in the body that offers a way to tackle and defeat some deadly blood cancers.

Dr. Jamieson – a researcher at the University of California, San Diego (UCSD) – has a paper published online today in The Lancet Haematology that highlights the safety and dosing levels for a new drug to treat a variety of blood cancers. CIRM funding helped Dr. Jamieson develop this work.

The drug targets cancer stem cells, the kind of cell that is believed to be able to lie dormant and evade anti-cancer therapies before springing back into action, causing a recurrence of the cancer. The drug coaxes the cancer stem cells out of their hiding space in the bone marrow and gets them to move into the blood stream where they can be destroyed by chemotherapy.

In a news release Dr. Jamieson says the drug – known by the catchy name of PF-04449913 – uses the sonic Hedgehog signaling pathway, an important regulator of the way we develop, to attack the cancer:

“This drug gets that unwanted house guest to leave and never come back. It’s a significant step forward in treating people with refractory or resistant myeloid leukemia, myelodysplastic syndrome and myelofibrosis. It’s a bonus that the drug can be administered as easily as an aspirin, in a single, daily oral tablet.”

The goal of this first-in-human study was to test the drug for safety; so 47 adults with blood and marrow cancer were given daily doses of the drug for up to 28 days. Those who were able to tolerate the dosage, without experiencing any serious side effects, were then given a higher dose for the next 28 days. Those who experienced problems were taken off the therapy.

Of the 47 people who started the trial in 2010, 28 experienced side effects. However, only three of those were severe. The drug showed signs of clinical activity – meaning it seemed to have an impact on the disease – in 23 people, almost half of those enrolled in the study.

Because of that initial promise it is now being tested in five different Phase 2 clinical trials. Dr. Jamieson says three of those trials are at UCSD:

“Our hope is that this drug will enable more effective treatment to begin earlier and that with earlier intervention, we can alter the course of disease and remove the need for, or improve the chances of success with, bone marrow transplantation. It’s all about reducing the burden of disease by intervening early.”

Goodnight, Stem Cells: How Well Rested Cells Keep Us Healthy

Plenty of studies show that a lack of sleep is nothing but bad news and can contribute to a whole host of health problems like heart disease, poor memory, high blood pressure and obesity.

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Even stem cells need rest to stay healthy

In a sense, the same holds true for the stem cells in our body. In response to injury, adult stem cells go to work by dividing and specializing into the cells needed to heal specific tissues and organs. But they also need to rest for long-lasting health. Each cell division carries a risk of introducing DNA mutations—and with it, a risk for cancer. Too much cell division can also deplete the stem cell supply, crippling the healing process. So it’s just as important for the stem cells to assume an inactive, or quiescent, state to maintain their ability to mend the body. Blood stem cells for instance are mostly quiescent and only divide about every two months to renew their reserves.

Even though the importance of this balance is well documented, exactly how it’s achieved is not well understood; that is, until now. Earlier this week, a CIRM-funded research team from The Scripps Research Institute (TSRI) reported on the identification of an enzyme that’s key in controlling the work-rest balance in blood stem cells, also called hematopoietic stem cells (HSCs). Their study, published in the journal Blood, could point the way to drugs that treat anemias, blood cancers, and other blood disorders.

Previous studies in other cell types suggested that this key enzyme, called ItpkB, might play a role in promoting a rested state in HSCs. Senior author Karsten Sauer explained their reasoning for focusing on the enzyme in a press release:

“What made ItpkB an attractive protein to study is that it can dampen activating signaling in other cells. We hypothesized that ItpkB might do the same in HSCs to keep them at rest. Moreover, ItpkB is an enzyme whose function can be controlled by small molecules. This might facilitate drug development if our hypothesis were true.”

Senior author Karsten Sauer is an associate professor at The Scripps Research Institute.

Senior author Karsten Sauer is an associate professor at The Scripps Research Institute.

To test their hypothesis, the team studied HSCs in mice that completely lacked ItpkB. Sure enough, without ItpkB the HSCs got stuck in the “on” position and continually multiplied until the supply of HSCs stores in the bone marrow were exhausted. Without these stem cells, the mice could no longer produce red blood cells, which deliver oxygen to the body or white blood cells, which fight off infection. As a result the animals died due to severe anemia and bone marrow failure. Sauer used a great analogy to describe the result:

“It’s like a car—you need to hit the gas pedal to get some activity, but if you hit it too hard, you can crash into a wall. ItpkB is that spring that prevents you from pushing the pedal all the way through.”

With this new understanding of how balancing stem cell activation and deactivation works, Sauer and his team have their sights set on human therapies:

“If we can show that ItpkB also keeps human HSCs healthy, this could open avenues to target ItpkB to improve HSC function in bone marrow failure syndromes and immunodeficiencies or to increase the success rates of HSC transplantation therapies for leukemias and lymphomas.”

Getting the right tools for the right job

Imagine a device that sits outside the body and works like a form of dialysis for a damaged liver, filtering out the toxins and giving the liver a chance to regenerate, and the patient a chance to avoid the need for a transplant.

Or imagine a method of enhancing the number of stem cells we can harvest or generate from umbilical cord blood, enabling us to use those stem cells and offer life-saving bone marrow transplants to all the patients who don’t have a matched donor.

Well, you may not have to imagine for too long. Yesterday, our governing Board approved almost $30 million in funding for our Tools and Technology Awards and two of the successful applications are for researchers hoping to turn those two ideas into reality.

The Tools n Tech awards may not have the glamor or cache of the big money awards that are developing treatments heading towards clinical trials, but they are nonetheless an essential part of what we do.

As our Board Chair Jonathan Thomas said in a news release they focus on developing new approaches or creating new ways of overcoming some of the biggest obstacles in stem cell research.

“Sometimes even the most promising therapy can be derailed by a tiny problem. These awards are designed to help find ways to overcome those problems, to bridge the gaps in our knowledge and ensure that the best research is able to keep progressing and move out of the lab and into clinical trials in patients.”

Altogether 20 awards were funded for a wide variety of different ideas and projects. Some focus on improving our ability to manufacture the kinds of cells we need for transplanting into patients. Another one plans to use a new class of genetic engineering tools to re-engineer the kind of stem cells found in bone marrow, making them resistant to HIV/AIDS. They also hope this method could ultimately be used to directly target the stem cells while they are inside the body, rather than taking the cells out and performing the same procedure in a lab and later transplanting them back.

Dr. Kent Leach, UC Davis School of Engineering

Dr. Kent Leach, UC Davis School of Engineering

One of the winners was Dr. Kent Leach from the University of California, Davis School of Engineering. He’s looking to make a new kind of imaging probe, one that uses light and sound to measure the strength and durability of bone and cartilage created by stem cells. This could eliminate the need for biopsies to make the same measurements, which is good news for patients and might also help reduce healthcare costs.

We featured Dr. Leach in one of our Spotlight videos where he talks about using stem cells to help repair broken bones that no longer respond to traditional methods.

Scientists Send Rodents to Space; Test New Therapy to Prevent Bone Loss

In just a few months, 40 very special rodents will embark upon the journey of a lifetime.

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Today UCLA scientists are announcing the start of a project that will test a new therapy that has the potential to slow, halt or even reverse bone loss due to disease or injury.

With grant funding from the Center for the Advancement of Science in Space (CASIS), a team of stem cell scientists led by UCLA professor of orthopedic surgery Chia Soo will send 40 rodents to the International Space Station (ISS). Living under microgravity conditions for two months, these rodents will begin to undergo bone loss—thus closely mimicking the conditions of bone loss, known as osteoporosis, seen in humans back on Earth.

At that point, the rodents will be injected with a molecule called NELL-1. Discovered by Soo’s UCLA colleague Kang Ting, this molecule has been shown in early tests to spur bone growth. In this new set of experiments on the ISS, the researchers hope to test the ability of NELL-1 to spur bone growth in the rodents.

The team is optimistic that NELL-1 could really be key to transforming how doctors treat bone loss. Said Ting in a news release:

“NELL-1 holds tremendous hope, not only for preventing bone loss but one day even restoring healthy bone. For patients who are bed-bound and suffering from bone loss, it could be life-changing.”

“Besides testing the limits of NELL-1’s robust bone-producing efforts, this mission will provide new insights about bone biology and could uncover important clues for curing diseases such as osteoporosis,” added Ben Wu, a UCLA bioengineer responsible for initially modifying NELL-1 to make it useful for treating bone loss.

The UCLA team will oversee ground operations while the experiments will be performed by NASA scientists on the ISS and coordinated by CASIS.

These experiments are important not only for developing new therapies to treat gradual bone loss, such as osteoporosis, which normally affects the elderly, but also those who have bone loss due to trauma or injury—including bone loss due to extended microgravity conditions, a persistent problem for astronauts living on the ISS. Said Soo:

“This research has enormous translational application for astronauts in space flight and for patients on Earth who have osteoporosis or other bone-loss problems from disease, illness or trauma.”

UC Davis Surgeons Begin Clinical Trial that Tests New Way to Deliver Stem Cells; Heal Bone Fractures

Each year, approximately 8.9 million people worldwide will suffer a bone fracture. Many of these fractures heal with the help of traditional methods, but for some, the road to recovery is far more difficult.

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After exhausting traditional treatments—such as surgically implanted pins or plates, bed rest and injections to spur bone growth—these patients can undergo a special type of stem cell transplant that directs stem cells extracted from the bone marrow to the fracture site to speed healing.

This procedure has its drawbacks, however. For example, the act of extracting cells from one’s own bone marrow and then injecting them into the fracture site requires two very painful surgical procedures: one to extract the cells, and another to implant them. Recovery times for each procedure, especially in older patients, can be significant.

Enter a team of surgeons at UC Davis. Who last week announced a ‘proof-of-concept’ clinical trial to test a device that can extract and isolate stem cells far more efficiently than before—and allow surgeons to implant the cells into the fracture in just a single surgery.

As described in HealthCanal, he procedure makes use of a reamer-irrigator-aspirator system, or RIA, that normally processes wastewater during bone drilling surgery. As its name implies, this wastewater was thought to be useless. But recent research has revealed that it is chock-full of stem cells.

The problem was that the stem cells were so diluted within the wastewater that they couldn’t be used. Luckily, a device recently developed by Sacramento-based SynGen, Inc., was able to quickly and efficiently extract the cells in high-enough concentrations to then be implanted into the patient. Instead of having to undergo two procedures—the patient now only has to undergo one.

“The device’s small size and rapid capabilities allow autologous stem cell transplantation to take place during a single operation in the operation room rather than requiring two procedures separated over a period of weeks,” said UC Davis surgeon Mark Lee, who is leading the clinical trial. “This is a dramatic difference that promises to make a real impact on healing and patient recovery.”

Hear more from Lee about how stem cells can be used to heal bone fractures in our 2012 Spotlight on Disease.

Stem cells and professional sports: a call for more science and less speculation

In the world of professional sports, teams invest tens of millions of dollars in players. Those players are under intense pressure to show a return on that investment for the team, and that means playing as hard as possible for as long as possible. So it’s no surprise that players facing serious injuries will often turn to any treatment that might get them back in the game.

image courtesy Scientific American

image courtesy Scientific American

A new study published last week in 2014 World Stem Cell Report (we blogged about it here) highlighted how far some players will go to keep playing, saying at least 12 NFL players have undergone unproven stem cell treatments in the last five years. A session at the recent World Stem Cell Summit in San Antonio, Texas showed that football is not unique, that this is a trend in all professional sports.

Dr. Shane Shapiro, an orthopedic surgeon at the Mayo Clinic, says it was an article in the New York Times in 2009 about two of the NFL players named in the World Stem Cell Report that led him to becoming interested in stem cells. The article focused on two members of the Pittsburgh Steelers team who were able to overcome injuries and play in the Super Bowl after undergoing stem cell treatment, although there was no direct evidence the stem cells caused the improvement.

“The next day, the day after the article appeared, I had multiple patients in my office with copies of the New York Times asking if I could perform the same procedure on them.”

Dr. Shapiro had experienced what has since become one of the driving factors behind many people seeking stem cell therapies, even ones that are unproven; the media reports high profile athletes getting a treatment that seems to work leading many non-athletes to want the same.

“This is not just about high profile athletes it’s also about older patients, weekend warriors and all those with degenerative joint disease, which affects around 50 million Americans. Currently for a lot of these degenerative conditions we don’t have many good non- surgical options, basically physical therapy, gentle pain relievers or steroid injections. That’s it. We have to get somewhere where we have options to slow down this trend, to slow down the progression of these injuries and problems.”

Shapiro says one of the most popular stem cell-based approaches in sports medicine today is the use of plasma rich platelets or PRP. The idea behind it makes sense, at least in theory. Blood contains platelets that contain growth factors that have been shown to help tissue heal. So injecting a patient’s platelets into the injury site might speed recovery and, because it’s the patient’s own platelets, the treatment probably won’t cause any immune response or prove to be harmful.

That’s the theory. The problem is few well-designed clinical trials have been done to see if that’s actually the case. Shapiro talked about one relatively small, non-randomized study that used PRP and in a 14-month follow-up found that 83% of patients reported feeling satisfied with their pain relief. However, 84% of this group did not have any visible improved appearance on ultrasound.

He is now in the process of carrying out a clinical trial, approved by the Food and Drug Administration (FDA), using bone marrow aspirate concentrate (BMAC) cells harvested from the patient’s own bone marrow. Because those cells secrete growth factors such as cytokines and chemokines they hope they may have anti-inflammatory and regenerative properties. The cells will be injected into 25 patients, all of whom have arthritic knees. They hope to have results next year.

Dr. Paul Saenz is a sports medicine specialist and the team physician for the San Antonio Spurs, the current National Basketball Association champions. He says that sports teams are frequently criticized for allowing players to undergo unproven stem cell treatments but he says it’s unrealistic to expect teams to do clinical studies to see if these therapies work, that’s not their area of expertise. But he also says team physicians are very careful in what they are willing to try.

“As fervent as we are to help bring an athlete back to form, we are equally fervent in our desire not to harm a $10 million athlete. Sports physicians are very conservative and for them stem cells are never the first thing they try, they are options when other approaches have failed.”

Saenz said while there are not enough double blind, randomized controlled clinical trials he has seen many individual cases, anecdotal evidence, where the use of stem cells has made a big difference. He talked about one basketball player, a 13-year NBA veteran, who was experiencing pain and mobility problems with his knee. He put the player on a biologic regimen and performed a PRP procedure on the knee.

“What we saw over the next few years was decreased pain, and a dramatic decrease in his reliance on non-steroidal anti inflammatory drugs. We saw improved MRI findings, improved athletic performance with more time on court, more baskets and more rebounds.”

But Saenz acknowledges that for the field to advance anecdotal stories like this are not enough, well-designed clinical trials are needed. He says right now there is too much guesswork in treatments, that there is not even any agreement on best practices or standardized treatment protocols.

Dr. Shapiro says for too long the use of stem cells in sports medicine has been the realm of individual physicians or medical groups. That has to change:

“If we are ever to move forward on this it has to be opened up to the scientific community, we have to do the work, do the studies, complete the analysis, open it up to our peers, report it in a reputable journal. If we want to treat the 50 million Americans who need this kind of therapy we need to go through the FDA approval process. We can’t just continue to treat the one patient a month who can afford to pay for all this themselves. “

No Fear of Rejection? Partial Stem Cell Transplant Reverses Sickle Cell Disease—even without Immunosuppressant Drugs

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.

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.

As lead author Dr. Matthew Hsieh noted in today’s press release:

“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.

Want to know more about how CIRM-funded scientists are working toward this goal? Check out our “Spotlight on Sickle Cell Disease.”