Funding stem cell research targeting a rare and life-threatening disease in children

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Photo courtesy Cystinosis Research Network

If you have never heard of cystinosis you should consider yourself fortunate. It’s a rare condition caused by an inherited genetic mutation. It hits early and it hits hard. Children with cystinosis are usually diagnosed before age 2 and are in end-stage kidney failure by the time they are 9. If that’s not bad enough they also experience damage to their eyes, liver, muscles, pancreas and brain.

The genetic mutation behind the condition results in an amino acid, cystine, accumulating at toxic levels in the body. There’s no cure. There is one approved treatment but it only delays progression of the disease, has some serious side effects of its own, and doesn’t prevent the need for a  kidney transplant.

Researchers at UC San Diego, led by Stephanie Cherqui, think they might have a better approach, one that could offer a single, life-long treatment for the problem. Yesterday the CIRM Board agreed and approved more than $5.2 million for Cherqui and her team to do the pre-clinical testing and work needed to get this potential treatment ready for a clinical trial.

Their goal is to take blood stem cells from people with cystinosis, genetically-modify them and return them to the patient, effectively delivering a healthy, functional gene to the body. The hope is that these genetically-modified blood stem cells will integrate with various body organs and not only replace diseased cells but also rescue them from the disease, making them healthy once again.

In a news release Randy Mills, CIRM’s President and CEO, said orphan diseases like cystinosis may not affect large numbers of people but are no less deserving of research in finding an effective therapy:

“Current treatments are expensive and limited. We want to push beyond and help find a life-long treatment, one that could prevent kidney failure and the need for kidney transplant. In this case, both the need and the science were compelling.”

The beauty of work like this is that, if successful, a one-time treatment could last a lifetime, eliminating or reducing kidney disease and the need for kidney transplantation. But it doesn’t stop there. The lessons learned through research like this might also apply to other inherited multi-organ degenerative disorders.

Asterias’ stem cell clinical trial shows encouraging results for spinal cord injury patients

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Jake Javier; Asterias spinal cord injury clinical trial participant

When researchers are carrying out a clinical trial they have two goals: first, show that it is safe (the old “do no harm” maxim) and second, show it works. One without the other doesn’t do anyone any good in the long run.

A few weeks ago Asterias Biotherapeutics showed that their CIRM-funded stem cell therapy for spinal cord injuries appeared to be safe. Now their data suggests it’s working. And that is a pretty exciting combination.

Asterias announced the news at the annual scientific meeting of the International Spinal Cord Society in Vienna, Austria. These results cover five people who got a transplant of 10 million cells. While the language is muted, the implications are very encouraging:

“While early in the study, with only 4 of the 5 patients in the cohort having reached 90 days after dosing, all patients have shown at least one motor level of improvement so far and the efficacy target of 2 of 5 patients in the cohort achieving two motor levels of improvement on at least one side of their body has already been achieved.”

What does that mean for the people treated? A lot. Remember these are people who qualified for this clinical trial because of an injury that left them pretty much paralyzed from the chest down. Seeing an improvement of two motor levels means they are regaining some use of their arms, hands and fingers, and that means they are regaining the ability to do things like feeding, dressing and bathing themselves. In effect, it is not only improving their quality of life but it is also giving them a chance to lead an independent life.

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Kris Boesen, Asterias clinical trial participant

One of those patients is Kris Boesen who regained the use of his arms and hands after becoming the first patient in this trial to get a transplant of 10 million cells. We blogged about Kris here

Asterias says of the 5 patients who got 10 million cells, 4 are now 90 days out from their transplant. Of those:

  • All four have improved one motor level on at least one side
  • 2 patients have improved two motor levels on one side
  • One has improved two motor levels on both sides

What’s also encouraging is that none of the people treated experienced any serious side effects or adverse events from the transplant or the temporary use of immunosuppressive drugs.

Steve Cartt, CEO of Asterias, was understandably happy with the news and that it allows them to move to the next phase:

“We are quite encouraged by this first look at efficacy results and look forward to reporting six-month efficacy data as planned in January 2017.  We have also just recently been cleared to begin enrolling a new cohort and administering to these new patients a much higher dose of 20 million cells.  We look forward to begin evaluating efficacy results in this higher-dose cohort in the coming months as well.”

People with spinal cord injuries can regain some function spontaneously so no one is yet leaping to the conclusion that all the progress in this trial is due to the stem cells. But to see all of the patients in the 10 million stem cell group do well is at the very least a positive sign. Now the hope is that these folks will continue to do well, and that the next group of people who get a 20 million cell transplant will also see improvements.

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Roman Reed, spinal cord injury patient advocate

While the team at Asterias were being cautiously optimistic, Roman Reed, whose foundation helped fund the early research that led to this clinical trial, was much less subdued in his response. He was positively giddy:

“If one patient only improves out of the five, it can be an outlier, but with everyone improving out of the five this is legit, this is real. Cures are happening!”

 

CIRM’s Randy Mills: New FDA rules for stem cells won’t fix the problem

For the last two days the Food and Drug Administration (FDA) has been holding a hearing in Bethesda, Maryland on new regulations that would tighten control over stem cell treatments. The FDA invited public testimony during the hearing on the regulations that would impact many of the clinics that currently offer unproven therapies

The testimony has been impassioned to say the least. Supporters of the clinics say they offer a valuable service and that patients should be allowed to decide for themselves how they want their own cells to be used. Opponents say the clinics are little more than snake oil sales people, offering bogus, unproven treatments.

One of those presenting was Randy Mills, CIRM’s President and CEO. Randy has been very vocal in the past about the need for the FDA to change the way it regulates stem cell therapies.

In California Healthline Randy explained why he thinks the rules the FDA is proposing will not fix the problem, and may even make it worse:

FDA Must Find A Middle Ground For Sake Of Patients

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Randy Mills

We aren’t happy, as a lot of people aren’t happy, with the proliferation of these stem cell clinics — some of which are probably doing good work. But some are clearly making rather outlandish claims for which there’s no real data. 

There are a couple of conditions coming together to create this storm.

One is that the need is very real. These patients are really struggling. They don’t have alternatives. They’re desperate and they need help. It’s not in the realm of possibility to talk to somebody who is suffering as badly as these patients are and to say, ‘You have to wait a few more decades for the science to catch up.’

On the other hand, we have a regulatory paradigm that only provides two pathways to put a cell therapy onto the market. One pathway is the most intense regulatory requirement anywhere in the world for any product — the biologics license application through the FDA, which takes 10 to 20 years and costs over $1 billion.

The other is through the exemptions the FDA has made, which require absolutely no pre-market approval whatsoever. You can be on the market in days, with no data.

The regulatory burden associated with one is massive and the other is almost nonexistent.

So it’s not at all surprising that we’re seeing a proliferation of these stem cell clinics popping up that are operating under the assumption that they fall under the exemption.

What the FDA is doing now is saying, ‘We’re not happy with this. We’re going to define some terms more narrowly than in the past … and make it more difficult to legally be on the market under the less burdensome regulatory pathway.’

That’s what this meeting is about.

The problem with their strategy is twofold. It doesn’t address the patients, or the need side of the equation. And I don’t think it has a chance of actually working because the FDA will acknowledge that they do not have the resources to enforce these types of regulations at the clinic level.

They would have to be essentially regulating the practice of physicians, which is well beyond their capabilities. Even if they were able to enforce it, it would just drive these patients somewhere else.

We’re advocating for the creation of some middle pathway that would bring essentially unregulated therapies into the regulatory fold, but in a manner which could be complied with.

I would rather know these clinics are being regulated and collecting data than have them operating under the radar screen of the FDA. I would like there to be a formal pre-market review of these therapies before they’re put on the market. I would like there to be safety and efficacy data.

I’m going to try hard to get the FDA to see that just plugging this hole won’t make the problem go away.

Thinking that they’re going to strengthen the regulation and that patients are going to be satisfied that there’s absolutely no chance for help is naive.

There isn’t a lot of evidence to suggest these types of procedures are overly risky. It’s not that they don’t have risk, but everything in medicine does. If you’re a patient who has absolutely no alternative, you’re probably willing to take the chance.

HOPE for patients with Duchenne Muscular Dystrophy-associated heart disease

It’s an exciting week for CIRM-funded clinical trials. Yesterday, we blogged about a young man named Kris Boesen who is responding positively to a stem cell therapy in a Phase 1/2a CIRM-funded clinical trial for spinal cord injury run by Asterias Biotherapeutics. Paralyzed from the chest down after a terrible car accident, Kris now has regained some use of his arms and hands following the stem cell transplant.

screen-shot-2016-09-08-at-9-18-46-amYesterday, Capricor Therapeutics also announced news about the progress of its CIRM-funded clinical trial that’s testing the safety and efficacy of a cardiac cell therapy called CAP-1002 for Duchenne Muscular Dystrophy-associated cardiomyopathy. Capricor has completed their Phase 1/2 trial enrollment of 25 patients. These patients are young boys (12 years of age or above) suffering from a build-up of scar tissue in their hearts due to DMD-associated cardiomyopathy. Reaching full enrollment is a key milestone for any clinical trial.

Duchenne Muscular Dystrophy (DMD) is an inherited disease that attacks muscle, causing muscle tissue to become weak and degenerate. The disease mainly appears in young boys between the ages of two and three. Patients with DMD often suffer from cardiomyopathy or weakened heart muscle caused by the thickening and hardening of the heart muscle and accumulation of scar tissue. DMD-associated cardiomyopathy is one of the leading causes of patient deaths.

President and CEO of Capricor, Dr. Linda Marban, believes there’s a potential for their CAP-1002 stem cell therapy to help DMD patients suffering from cardiomyopathy. She explained in a press release:

“In DMD, scar tissue progressively aggregates in the heart, leading to a deterioration of cardiac function for which treatment options are limited. We believe CAP-1002 is the only therapeutic candidate in development for the treatment of DMD that has been clinically shown to reduce scar tissue in the damaged heart.”

The Capricor trial was approved by the CIRM Board in March 2016 and since then Capricor has worked quickly to enroll patients in its HOPE-Duchenne trial (HOPE stands for Halt cardiomyopathy progression in Duchenne).

Dr. Marban commented on the trials recent progress:

Linda Marban, CEO of Capricor Therapeutics

Linda Marban, CEO of Capricor Therapeutics

“The rate of patient enrollment into HOPE-Duchenne far surpassed our expectations, signifying the need for therapeutic options as well as the desire of the DMD community to address the heart disease that is highly prevalent in this population. We look forward to announcing top-line six-month results from HOPE-Duchenne in the first quarter of next year, in which we will report on the safety as well as the potential efficacy of CAP-1002.”

Half of the enrolled patients will receive an infusion of the CAP-1002 cardiac cell therapy while the other half will receive regular care without the infusion. Capricor will monitor all these patients to make sure that the cell therapy is well tolerated and doesn’t cause any harm. It will also look for any positive signs that the therapy is benefiting patients using a series of tests that measure changes in scar tissue and heart function.

HOPE is high for this trial to succeed as there is currently no treatment that can successfully reduce the amount of cardiac scar tissue in patients suffering from DMD-associated cardiomyopathy. The Capricor trial is in its early stages, but check in with the Stem Cellar for an update on the safety and efficacy data from this trial in early 2017.


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Young man with spinal cord injury regains use of hands and arms after stem cell therapy

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Kris Boesen – Photo courtesy USC

Hope is such a fragile thing. We cling to it in bad times. It offers us a sense that we can bear whatever hardships we are facing today, and that tomorrow will be better.

Kris Boesen knows all about holding on to hope during bad times. On March 6th of this year he was left paralyzed from the neck down after a car accident. Kris and his parents were warned the damage might be permanent.

Kris says at that point, life was pretty bleak:

“I couldn’t drink, couldn’t feed myself, couldn’t text or pretty much do anything, I was basically just existing. I wasn’t living my life, I was existing.”

For Kris and his family hope came in the form of a stem cell clinical trial, run by Asterias Biotherapeutics and funded by CIRM. The Asterias team had already enrolled three patients in the trial, each of whom had 2 million cells transplanted into their necks, primarily to test for safety. In early April Kris became the first patient in the trial to get a transplant of 10 million stem cells.

Within two weeks he began to show signs of improvement, regaining movement and strength in his arms and hands:

“Now I have grip strength and do things like open a bottle of soda and feed myself. Whereas before I was relying on my parents, now after the stem cell therapy I am able to live my life.”

The therapy involves human embryonic stem cells that have been differentiated, or converted, into cells called oligodendrocyte progenitors. These are capable of becoming the kind of cells which help protect nerve cells in the central nervous system, the area damaged in spinal cord injury.

The surgery was performed by Keck Medicine of USC’s Dr. Charles Liu. In a news release about the procedure, he says improvements of the kind Kris has experienced can make a huge difference in someone’s life:

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Dr. Charles Liu, Keck School of Medicine: Photo courtesy USC

“As of 90 days post-treatment, Kris has gained significant improvement in his motor function, up to two spinal cord levels. In Kris’ case, two spinal cord levels means the difference between using your hands to brush your teeth, operate a computer or do other things you wouldn’t otherwise be able to do, so having this level of functional independence cannot be overstated.”

We blogged about this work as recently as last week, when Asterias announced that the trial had passed two important safety hurdles.  But Kris’ story is the first to suggest this treatment might actually be working.

Randy Mills, CIRM’s President & CEO, says:

 “With each patient treated in this clinical trial we learn.  We gain more experience, all of which helps us put into better context the significance of this type of event for all people afflicted with debilitating spinal cord injuries. But let us not lose sight of the individual here.  While each participant in a clinical trial is part of the group, for them success is binary.  They either improve or they do not.  Kris bravely and selflessly volunteered for this clinical trial so that others may benefit from what we learn.  So it is fitting that today we celebrate Kris’ improvements and stop to thank all those participating in clinical trials for their selfless efforts.”

For patient advocates like Roman Reed, this was a moment to celebrate. Roman has been championing stem cell research for years and through his Roman Reed Foundation helped lay the groundwork for the research that led to this clinical trial:

This is clear affirmative affirmation that we are making Medical History!  We were able to give a paralyzed quadriplegic patient back the use of his hands! With only half a clinical dosage. Now this person may hold and grasp his loved ones hands in his own hands because of the actions of our last two decades for medical research for paralysis CURE! CARPE DIEM!”

It’s not unheard of for people with the kind of injury Kris had to make a partial recovery, to regain some use of their arms and hands, so it’s impossible to know right now if the stem cell transplant was the deciding factor.

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Kris at home: photo courtesy USC

Kris’ dad, Rodney, says he doesn’t care how it happened, he’s just delighted it did:

“He’s going to have a life, even if (the progress) stops just this second, and this is what he has, he’s going to have a better life than he would have definitely had before, because there are so many things that this opens up the world for him, he’s going to be able to use his hands.”

Clearing the first hurdle: spinal cord injury trial passes safety review

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Jake Javier, participant in Asterias clinica trial

Starting a clinical trial is like taking a step into the unknown. It’s moving a potential therapy out of the lab and testing it in people. To reach this point the researchers have done a lot of work trying to ensure the therapy is safe. But that work was done in the lab, and on mice or other animals. Now it’s time to see what happens when you try it in the real world.

It can be quite nerve wracking for everyone involved: both the researchers, because years of hard work are at stake, and the patients, because they’re getting something that has never been tested in humans before; something that could, potentially, change their lives.

Today we got some good news about one clinical trial we are funding, the Asterias Biotherapeutics spinal cord injury trial. Asterias announced that its Data Monitoring Committee (DMC) has reviewed the safety data from the first two groups of patients treated and found no problems or bad side effects.

That’s an important first step in any clinical trial because it shows that, at the very least, the therapy is not going to make the patient’s condition any worse.

The big question now, is will it make their condition better? That’s something we’ll come back to at a later date when we have a better idea how the people treated in the trial are doing. But for now let’s take a deeper dive into the safety data.

Asterias – by the numbers

This current trial is a Phase 1/2a trial. The people enrolled have all experienced injuries in the C5-C7 vertebrae – that’s high up in the neck – and have essentially lost all feeling and movement below the injury site. All are treated between two weeks and one month after the injury was sustained.

The therapy involves transplants of Asterias’ AST-OPC1 cells which were made from human embryonic stem cells. The AST-OPC1 cells have been turned into oligodendrocyte progenitors, which are capable of becoming the kind of cells which help protect nerve cells in the central nervous system, the area damaged in spinal cord injury.

The first group of three patients in the Asterias trial was given 2 million cells. The second group of five patients received 10 million cells. The DMC said the safety data from those patients looked fine, that there were no signs of problems.

As Dr. Edward Wirth, the Chief Medical Officer at Asterias, said in a news release, this means the company can plan for its next phase:

“The positive safety data in the previous phase 1 study and in the ongoing phase 1/2a study gives us the confidence to now proceed to administration of 20 million cells, which based on our significant pre-clinical research is likely well within the dosing range where we would expect to see clinically meaningful improvement in these patients.”

Asterias is now looking to enroll 5-8 patients for this 20 million cell phase.

jake and family

For people like Jake Javier this news is not about numbers or data, it’s personal. Earlier this summer Jake broke his neck at a pool party, celebrating graduating from high school. It left him paralyzed from the chest down with extremely limited use of his arms and hands. On July 7th Jake was enrolled in the Asterias trial, and had ten million cells transplanted into his neck.

It could be months, even as much as one year, before we know if those cells are having any beneficial effect on Jake. But at least for now we know they don’t seem to be having any negative effects.

“First do no harm” is the cardinal rule that all budding physicians are taught. This trial seems to be meeting that benchmark. Our hope now is that it will do a lot more, and truly make a difference in the lives of people like Jake.

As Randy Mills, CIRM’s President and CEO, said in a news release:

“I recently met with Jake and heard first-hand what he and his family are going through in the aftermath of his injury. But I also saw a young man with remarkable courage and determination. It is because of Jake, and the others who volunteer to take part in clinical trials, that progress is possible. They are true heroes.”


* On a side note, Roman Reed, a great champion of stem cell research and a patient advocate extraordinaire, helped make much of this story happen. He helped Jake enroll in the Asterias trial ,and the research that led to this therapy was pioneered by Dr. Hans Keirstead who was funded by the Roman Reed Spinal Cord Injury Research Act.

 

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Seeing is believing: how some scientists – including two funded by CIRM – are working to help the blind see

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How retinitis pigmentosa destroys vision – new stem cell research may help reverse that

“A pale hue”. For most of us that is a simple description, an observation about color. For Kristin Macdonald it’s a glimpse of the future. In some ways it’s a miracle. Kristin lost her sight to retinitis pigmentosa (RP). For many years she was virtually blind. But now, thanks to a clinical trial funded by CIRM she is starting to see again.

Kristin’s story is one of several examples of restoring sight in an article entitled “Why There’s New Hope About Ending Blindness” in the latest issue of National Geographic.  The article explores different approaches to treating people who were either born without vision or lost their vision due to disease or injury.

Two of those stories feature research that CIRM has funded. One is the work that is helping Kristin. Retinitis pigmentosa is a relatively rare condition that destroys the photoreceptors at the back of the eye, the cells that actually allow us to sense light. The National Geographic piece highlights how a research team at the University of California, Irvine, led by Dr. Henry Klassen, has been working on a way to use stem cells to replace and repair the cells damaged by RP.

“Klassen has spent 30 years studying how to coax progenitor cells—former stem cells that have begun to move toward being specific cell types—into replacing or rehabilitating failed retinal cells. Having successfully used retinal progenitor cells to improve vision in mice, rats, cats, dogs, and pigs, he’s testing a similar treatment in people with advanced retinitis pigmentosa.”

We recently blogged about this work and the fact that this team just passed it’s first major milestone – – showing that in the first nine patients treated none experienced any serious side effects. A Phase 1 clinical trial like this is designed to test for safety, so it usually involves the use of relatively small numbers of cells. The fact that some of those treated, like Kristin, are showing signs of improvement in their vision is quite encouraging. We will be following this work very closely and reporting new results as soon as they are available.

The other CIRM-supported research featured in the article is led by what the writer calls “an eyeball dream team” featuring University of Southern California’s Dr. Mark Humayun, described as “a courteous, efficient, impeccably besuited man.” And it’s true, he is.

The team is developing a stem cell device to help treat age-related macular degeneration, the leading cause of vision loss in the US.

“He and his fellow principal investigator, University of California, Santa Barbara stem cell biologist Dennis Clegg, call it simply a patch. That patch’s chassis, made of the same stuff used to coat wiring for pacemakers and neural implants, is wafer thin, bottle shaped, and the size of a fat grain of rice. Onto this speck Clegg distributes 120,000 cells derived from embryonic stem cells.”

Humayun and Clegg have just started their clinical trial with this work so it is likely going to be some time before we have any results.

These are just two of the many different approaches, using several different methods, to address vision loss. The article is a fascinating read, giving you a sense of how science is transforming people’s lives. It’s also wonderfully written by David Dobbs, including observations like this:

“Neuroscientists love the eye because “it’s the only place you see the brain without drilling a hole,” as one put it to me.”

For a vision of the future, a future that could mean restoring vision to those who have lost it, it’s a terrific read.

 

How many stem cell trials will it take to get a cure?

When I think about how many clinical trials it will take before a stem cell therapy is available to patients, I’m reminded of the decades old Tootsie Pop commercial where a kid asks a series of talking animals, “How many licks does it take to get to the Tootsie Roll center of a Tootsie Pop?”

While Mr. Cow, Mr. Fox, and Mr. Turtle are all stumped, Mr. Owl tackles the question like a true scientist:

“A good question. Let’s find out. [Takes Tootsie pop and starts licking]. A One…A Two-hoo…A Three-hee. [Insert loud crunching sounds] A Three!”

The commercial ends with the narrator concluding that the world may never know how many licks it takes to get to the center (because Mr. Owl failed to complete his experiment…not a true scientist after all).

What do Tootsie Pops have to do with stem cell therapies?

I’m not saying that the Tootsie Pop question holds the same level of importance as the question of when scientists will develop a stem cell therapy that cures a disease, but I find it representative of the confusion and uncertainty that the general public has about when the “promise of stem cell research” will become a reality.

Let me explain…

Mr. Owl claims that it only takes three licks to get to the center of a Tootsie Pop, but three licks obviously aren’t enough to get through the hard candy exterior to the chewy tootsie center. According to the Tootsie “Scientific Endeavors” page, “at least three detailed scientific studies” determined that it takes between 144-411 licks to get to the center. My intuition is to go with the scientists, but depending on how the experiment was conducted or maybe the size of the tongue used, the final answer could vary.

Embryonic stem cells

Embryonic stem cells

For stem cell clinical trials, the situation is similar. The first clinical trial approved in the U.S. using human embryonic stem cells was in 2009. Since then, hundreds of clinical trials have been conducted globally using pluripotent – either embryonic or induced pluripotent stem cells (iPSCs) – or adult stem cells. But so far, none have made their way routinely to patients outside of a clinical trial setting in the U.S., (although a few stem cell-based products have been approved in other countries), and it’s unclear how many more trials it will take to get to this point.

Part of this murkiness is because we’re still in the early days of stem cell research: human embryonic stem cells were first isolated by James Thomson in 1998, and iPSCs weren’t discovered by Shinya Yamanaka until 2006. Scientists need more time to conduct preclinical research to understand how these stem cells can be best used to treat certain diseases and what stem cells will do when transplanted into patients.

Another other issue is that the U.S. Food and Drug Administration (FDA) has only approved one stem cell therapy – cord blood stem cell transplantation – for commercial use in 2011 and none since then. A big debate is currently ongoing about whether the regulatory landscape needs to change so that stem cell treatments that show promise in trials can get to patients who desperately need them.

Hopefully soon, the FDA will adopt a more efficient strategy for approving stem cell therapies that still keeps patient safety at the forefront. Otherwise it could take a lot longer for newer stem cell technologies like iPSCs to make their way to the clinic (although we’ve seen some encouraging preliminary results using iPSC-based therapy in clinical trials for blindness).

Trial, trial, trial again

So how many clinical trials will it take for a stem cell therapy to succeed sufficiently to gain approval and when will that happen?

Unfortunately, we don’t know the answers to these questions, but we do know that scientists need to continue to develop and test new stem cell treatments in human trials if we want to see any progress.

At CIRM, we are currently funding 16 clinical trials involving stem cell therapies for cancer, heart failure, diabetes, spinal cord injury and other diseases. But we need to fund more trials to increase the odds that some will make it through the gauntlet and prove both safe and effective at treating patients. Our goal now is to fund 50 clinical trials in the next five years. It’s an aggressive plan, but one we feel will hopefully take stem cell therapies from promise to reality.

We also know that CIRM is a soldier in a large army of funding agencies, universities, companies, and scientists around the world battling against time to develop stem cell therapies that could help patients in their lifetimes. And with this stem cell army, we believe we’re getting closer to the chewy center of the Tootsie pop, or in this case, an approved stem cell therapy for patients desperate for a cure.

This blog was written as part of the CCRM Signals iPSC anniversary blog carnival. Please click here to read what other bloggers have to say about the future of stem cells and regenerative medicine.

New approach could help turn back the clock and reverse damage for stroke patients

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Stroke: courtesy WebMD

Stroke is the leading cause of serious, long-term disability in the US. Every year almost 800,000 people suffer from a stroke. The impact on their lives, and the lives of those around them can be devastating.

Right now the only treatment approved by the US Food and Drug Administration (FDA) is tissue plasminogen activator or tPA. This helps dissolve the blood clot causing most strokes and restores blood flow to the brain. However, to be fully effective this has to be administered within about 3-4 hours after the stroke. Many people are unable to get to the hospital in time and as a result suffer long-term damage, damage that for most people has been permanent.

But now a new study in Nature Medicine shows that might not be the case, and that this damage could even be reversible.

The research, done by a team at the University of Southern California (USC) uses a one-two punch combination of stem cells and a protein that helps those cells turn into neurons, the cells in the brain damaged by a stroke.

First, the researchers induced a stroke in mice and then transplanted human neural stem cells alongside the damaged brain tissue. They then added in a dose of the protein 3K3A-APC or a placebo.

hey found that mice treated with 3K3A-APC had 16 times more human stem-cell derived neurons than the mice treated with the placebo. Those neurons weren’t just sitting around doing nothing. USC’s Berislav Zlokovic, senior author of the paper, says they were actively repairing the stroke-induced damage.

“We showed that 3K3A-APC helps the grafted stem cells convert into neurons and make structural and functional connections with the host’s nervous system. No one in the stroke field has ever shown this, so I believe this is going to be the gold standard for future studies. Functional deficits after five weeks of stroke were minimized, and the mice were almost back to normal in terms of motor and sensorimotor functions. Synapses formed between transplanted cells and host cells, so there is functional activation and cooperation of transplanted cells in the host circuitry.”

The researchers wanted to make sure the transplanted cell-3K3A-ACP combination was really the cause of the improvement in the mice so they then used what’s called an “assassin toxin” to kill the neurons they had created. That reversed the improvements in the treated mice, leaving them comparable to the untreated mice. All this suggests the neurons had become an integral part of the mouse’s brain.

So how might this benefit people? You may remember that earlier this summer Stanford researchers produced a paper showing they had helped some 18 stroke patients, by injecting stem cells from donor bone marrow into their brain. The improvements were significant, including in at least one case regaining the ability to walk. We blogged about that work here

In that study, however, the cells did not become neurons nor did they seem to remain in the brain for an extended period. It’s hoped this new work can build on that by giving researchers an additional tool, the 3K3A-ACP protein, to help the transplanted cells convert to neurons and become integrated into the brain.

One of the other advantages of using this protein is that it has already been approved by the FDA for use in people who have experienced an ischemic stroke, which accounts for about 87 percent of all strokes.

The USC team now hope to get approval from the FDA to see if they can replicate their experiences in mice in people, through a Phase 2 clinical trial.

 

 

 

 

 

 

 

Better, Faster Quality Control for Stem Cell-Based Therapies

“Based”.

It’s a pretty boring word but I make sure to include it when writing about the development of stem cell therapies, as in: “Asterias Biotherapeutics is testing an embryonic stem cell-based treatment for spinal cord injury”. It’s a key word here because no legitimate clinic would transplant embryonic stem cells (ESCs) or induced pluripotent stem cells (iPSCs) directly into a patient. The ability of these cells to make unlimited copies of themselves is great for growing them in the lab; but in the body, that same property presents a very real risk of tumor formation. Instead, ESCs and iPSCs are merely the base material from which specialized cells are matured from for the many promising therapies being developed for clinical trials.

To ensure safety to patients, minimizing the number of these potentially cancer-causing pluripotent stem cells still lingering in a cell therapy product is one of the main safety concerns of the Food and Drug Administration (FDA), the U.S. federal agency that approves therapies for clinical trials. So during therapy development, researchers run assays, or tests, to detect how many ESCs or iPSCs remain in their cell product and if they can form tumors.

In a paper published yesterday in Biomaterials, an Emory University research team reported on the development of a new technique that is several thousand-fold (!!!) higher in sensitivity than current assays and could be a game-changer for the quality control of stem cell-based therapies (also see an Emory U. blog about the study).

Surface-enhanced Raman Scattering Assay: it’s one in a million

SERS-schematic

Illustrated overview of the SERS assay workflow (Image: Biomaterials)

In the technique, called a surface-enhanced Raman scattering (SERS) assay, gold nanoparticles are attached to proteins, called antibodies, that specifically bind to the surface of stem cells. These antibody-nanoparticles are mixed with a preparation of the cell product. A laser is then directed at the cells and a device, called a spectrometer, measures the resulting light scatter which ultimately can be converted into the number of stem cells in the cell mix.

Incredibly, this assay can detect one stem cell out of one million specialized cells making it well suited for testing clinical grade cell therapy products. In comparison, the current flow cytometry technique which uses fluorescently tagged antibodies, can spot 1 stem cell in about 1000 cells.

Another current way to detect stem cells in a cell product is through the so-called teratoma assay. In this test, a mouse is injected with the cell therapy and observed for about three months to see if any teratomas, or tumors, form from residual stem cells. While this technique is a more direct safety test, it’s very costly, time-consuming, and impractical for testing very large doses of cell therapies. As the authors mention in the publication, the SERS technique could help overcome the limitations of both the teratoma and flow cytometry assays:

“Because of their remarkable sensitivity, these SERS assays may facilitate safety assessment of cell preparations for transplantations that require a large quantity of cells, which is unachievable using flow cytometry or the teratoma assay in mice. In addition, these assays are cost-effective, easy to use, and can be done within an hour, which is much faster than the traditional teratoma assay.”

“Faster”. Now that’s a pretty exciting word I always like to include when writing about the development of stem cell therapies.