Mark Humayun

How a tiny patch is helping restore lasting vision

/ Kevin McCormack / 4 Comments

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Researchers are working on a stem cell-based retinal implant that could be used for people with with advanced dry age-related macular degeneration. (Photo/ Britney O. Pennington)

When Anna Kuehl began losing her vision, she feared losing the ability to read and go on long walks in nature—two of her favorite pastimes. Anna had been diagnosed with age-related macular degeneration, the leading cause of vision loss in the US. She lost the central vision in her left eye, which meant she could no longer make out people’s faces clearly, drive a car, or read the time on her watch.

Anna Kuehl

But a clinical trial funded by the California Institute for Regenerative Medicine  (CIRM) helped change that. And now, new data from that trial shows the treatment appears to be long lasting.

The treatment sprang out of research done by Dr. Mark Humayun and his team at USC. In collaboration with Regenerative Patch Technologies they developed a stem cell-derived implant using cells from a healthy donor. The implant was then placed under the retina in the back of the eye. The hope was those stem cells would then repair and replace damaged cells and restore some vision.

Dr. Mark Humayun, photo courtesy USC

In the past, using donor cells meant that patients often had to be given long-term immunosuppression to stop their body’s immune system attacking and destroying the patch. But in this trial, the patients were given just two months of immunosuppression, shortly before and after the implant procedure.

In a news story on the USC website, Dr. Humayun said this was an important advantage. “There’s been some debate on whether stem cells derived from a different, unrelated person would survive in the retina without long-term immunosuppression. For instance, if you were to receive a kidney transplant, long-term immunosuppression would be required to prevent organ rejection. This study indicates the cells on the retinal implant can survive for up to two years without long-term immunosuppression.”

Cells show staying power

When one of the patients in the clinical trial died from unrelated causes two years after getting the implant, the research team were able to show that even with only limited immunosuppression, there was no evidence that the patient’s body was rejecting the donor cells.

“These findings show the implant can improve visual function in some patients who were legally-blind before treatment and that the cells on the implant survive and remain functional for at least two years despite not being matched with those of the patient,” Humayun said.

For Anna Kuehl, the results have been remarkable. She was able to read an additional 17 letters on a standard eye chart. Even more importantly, she is able to read again, and able to walk and enjoy nature again.

Dr. Humayun says the study—published in the journal Stem Cell Reports—may have implications for treating other vision-destroying diseases. “This study addresses the debate over the viability of using mismatched stem cells — this shows that a mismatched stem cell derived implant can be safe and viable over multiple years.”

CIRM funded trial for AMD shows promising results

/ Yimy Villa / 13 Comments

This upcoming July is healthy vision month, a time to remember the importance of making vision and eye health a priority. It’s also a time to think about the approximately 12 million people, 40 and over in the United States, that have a vision impairment. Vision can be something that many of us take for granted, but losing even a portion of it can have a profound impact on our everyday life. It can impact your ability to do everyday things, from basic hygiene routines and driving to hobbies such as reading, writing, or watching a film.

It is because of this that CIRM has made vision related problems a priority, providing over $69 million in funding for six clinical trials related to vision loss. There is reason to be hopeful as these trials have demonstrated promising results. One of these trials, conducted by Regenerative Patch Technologies LLC (RPT), announced today results from its CIRM funded clinical trial ($16.3 million) for advanced, dry age-related macular degeneration (AMD).

AMD is a progressive disease resulting in death of the retinal pigment epithelium (RPE), an area of the eye that plays a key role in maintaining vision. Damage to the RPE causes distortion to central vision and eventually leads to legal blindness. Thanks to CIRM funding, RPT and scientists at the University of Southern California (USC) and UC Santa Barbara (UCSB) are growing specialized RPE cells from human embryonic stem cells (hESCs), placing them on a single layer scaffold, and implanting the combination device in the back of the eye to try to reverse the blindness caused by AMD.

One of the trial participants is Anna Kuehl, a USC alumna and avid nature lover. She was diagnosed with AMD in her mid 30s and gradually began losing the central vision in her left eye. Although her peripheral vision remained intact, she could no longer make out people’s faces clearly, drive a car, or read the time on her watch. This also meant she would have much more difficulty going on the nature hikes she enjoys so much. After receiving treatment, she noticed improvements in her vision.

Anna was not alone in these improvements post treatment. The implant, known as CPCB-RPE1, was delivered to the worst eye of 15 patients with AMD. All treated eyes were legally-blind having a best corrected visual acuity (BCVA) of 20/200 or worse (20/20 indicates perfect vision).

Patients in the clinical trial were assessed for visual function and the results were as follows:

  • At an average of 34 months post-implantation (range 12-48 months), 27% (4/15) showed a greater than 5 letter improvement in BCVA and 33% (5/15) remained stable with a BCVA within 5 letters of baseline value. The improvements ranged from 7-15 letters or 1-3 lines on an eye chart.
  • In contrast, BCVA in the fellow, untreated eye declined by more than 5 letters (range 8-21 letters or 1-4 lines on an eye chart) in 80% (12/15) of subjects. There was no improvement in BCVA in the untreated eye of any subject. 
  • The implant was delivered safely and remained stably in place throughout the trial.
  • Refinements to the implantation procedure during the trial further improved its efficiency and safety profile.

In a news release from RPT, Mark Humayun, M.D., Ph.D., founder and co-owner of RPT, Director of the USC Ginsburg Institute for Biomedical Therapeutics and Co-Director of the USC Roski Eye Institute, Keck Medicine of USC, had this to say about the trial results.

“The improvements in best corrected visual acuity observed in some eyes receiving the implant are very promising, especially considering the very late stage of their disease. Improvements in visual acuity are exceedingly rare in geographic atrophy as demonstrated by the large decline in vision in many of the untreated eyes which also had disease. There are currently no approved therapies for this level of advanced dry age-related macular degeneration”. 

The full presentation can be found on RPT’s website linked here.

Watch the video below to learn more about Anna’s story.

CIRM-funded study helps unlock some of the genetic secrets behind macular degeneration

/ Kevin McCormack / Leave a comment
Retina affected by age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of vision loss in people over 60. It affects 10 million Americans. That’s more than cataracts and glaucoma combined. The causes of AMD are not known but are believed to involve a mixture of hereditary and environmental factors. There is no treatment for it.

Now, in a CIRM-funded study, researchers at UC San Diego (UCSD) have used stem cells to help identify genetic elements that could provide some clues as to the cause, and maybe give some ideas on how to treat it.

Before we get into what the researchers did let’s take a look at what AMD does. At a basic level it attacks the retina, the thin layer of tissue that lines the back of the eye. The retina receives light, turns it into electrical signals and sends it to the brain which turns it into a visual image.

The disease destroys the macula, the part of the retina that controls our central vision. At first, sight becomes blurred or fuzzy but over time it progresses to the point where central vision is almost completely destroyed.

To try and understand why this happens the team at UCSD took skin samples from six people with AMD and, using the iPSC method, turned those cells into the kinds of cell found in the retina. Because these cells came from people who had AMD they now displayed the same characteristics as AMD-affected retinal cells. This allowed the researchers to create what is called a “disease-in-a-dish” model that allowed them to see, in real time, what is happening in AMD.

They were able to identify a genetic variant that reduces production of a protein called VEGFA, which is known to promote the growth of new blood vessels.

In a news release Kelly Frazer, director of the Institute for Genomic Medicine at UCSD and the lead author of the study, said the results were unexpected.

Kelly Frazer, PhD, UC San Diego

“We didn’t start with the VEGFA gene when we went looking for genetic causes of AMD. But we were surprised to find that with samples from just six people, this genetic variation clearly emerged as a causal factor.”

Frazer says this discovery, published in the journal Stem Cell Reports, could ultimately lead to new approaches to developing new treatments for AMD.

CIRM already funds one clinical trial-stage project targeting AMD.

The moment of truth. A video about the stem cell therapy that could help millions of people going blind.

/ Kevin McCormack / 1 Comment

“No matter how much one prepares, the first patient is always something very special.” That’s how Dr. Mark Humayun describes his feelings as he prepared to deliver a CIRM-funded stem cell therapy to help someone going blind from dry age-related macular degeneration (AMD).

Humayun, an ophthalmologist and stem cell researcher at USC, spent years developing this therapy and so it’s understandable that he might be a little nervous finally getting a chance to see if it works in people.

It’s quite a complicated procedure, involving turning embryonic stem cells into the kind of cells that are destroyed by AMD, placing those cells onto a specially developed synthetic scaffold and then surgically implanting the cells and scaffold onto the back of the eye.

There’s a real need for a treatment for AMD, the leading cause of vision loss in the US. Right now, there is no effective therapy for AMD and some three million Americans are facing the prospect of losing their eyesight.

The first, preliminary, results of this trial were released last week and they were encouraging. You can read about them on our blog.

Thanks to USC you can also see the team that developed and executed this promising approach. They created a video capturing the moment the team were finally taking all that hard work and delivering it where it matters, to the patient.

Watching the video it’s hard not to think you are watching a piece of history, something that has the potential to do more than just offer hope to people losing their vision, it has the potential to stop and even reverse that process.

The video is a salute to the researchers who developed the therapy, and the doctors, nurses and Operating Room team who delivered it. It’s also a salute to the person lying down, the patient who volunteered to be the first to try this. Everyone in that room is a pioneer.

Encouraging news about CIRM-funded clinical trial targeting vision loss

/ Kevin McCormack / 3 Comments

dry AMD

An eye affected by dry age-related macular degeneration

Dry age-related macular degeneration (AMD) is the leading cause of vision loss in the U.S. By 2020 it’s estimated that as many as three million Americans will be affected by the disease. Right now, there is no effective therapy. But that could change. A new CIRM-funded clinical trial is showing promise in helping people battling the disease not just in stabilizing their vision loss, but even reversing it.

In AMD, cells in the retina, the light-sensitive tissue at the back of the eye, are slowly destroyed affecting a person’s central vision. It can make it difficult to do everyday activities such as reading or watching TV and make it impossible for a person to drive.

Researchers at the University of Southern California (USC) Roski Eye Institute at the Keck School of Medicine, and Regenerative Patch Technologies, have developed a therapy using embryonic stem cells that they turned into retinal pigment epithelium (RPE) cells – the kind of cell destroyed by AMD. These cells were then placed on a synthetic scaffold which was surgically implanted in the back of the eye.

Imaging studies showed that the RPE cells appeared to integrate well into the eye and remained in place during follow-up tests 120 to 365 days after implantation.

Encouraging results

Of the five patients enrolled in the Phase 1/2a trial, four maintained their vision in the treated eye, two showed improvement in the stability of their vision, and one patient had a 17-letter improvement in their vision on a reading chart. In addition, there were no serious side effects or unanticipated problems.

There were other indications the implants were proving beneficial.  People with normal vision have the ability to focus their gaze on a single location. People with advanced AMD lose that ability. In this trial, two of the patients recovered stable fixation. These improvements were maintained in follow-up tests.

Abla-8

Abla Creasey, Ph.D., CIRM’S Vice President of Therapeutics and Strategic Infrastructure says even these small benefits are important:

“Having a therapy with a favorable safety profile, that could slow down the progression, or even reverse the vision loss would benefit millions of Americans. That’s why these results, while still in an early stage are encouraging, because the people treated in the trial are ones most severely affected by the disease who have the least potential for visual recovery.”

This study reflects CIRM’s long-term commitment to supporting the most promising stem cell research. The Stem Cell Agency began supporting USC’s Dr. Mark Humayun, the lead inventor of the implant, in 2010 and has been a partner with him and his team since then.

Dr.MarkHumayun2 copy

In a news release Dr. Humayun said they plan to recruit another 15 patients to see if these results hold up:

“Our study shows that this unique stem cell–based retinal implant thus far is well-tolerated, and preliminary results suggest it may help people with advanced dry age-related macular degeneration.”

While the results, published in the journal Science Translational Medicine, are encouraging the researchers caution that this was a very early stage clinical trial, with a small number of patients. They say the next step is to continue to follow the four patients treated in this trial to see if there are any further changes to their vision, and to conduct a larger trial.

 

 

Three people left blind by Florida clinic’s unproven stem cell therapy

/ Kevin McCormack / 8 Comments

Unproven treatment

Unproven stem cell treatments endanger patients: Photo courtesy Healthline

The report makes for chilling reading. Three women, all suffering from macular degeneration – the leading cause of vision loss in the US – went to a Florida clinic hoping that a stem cell therapy would save their eyesight. Instead, it caused all three to go blind.

The study, in the latest issue of the New England Journal of Medicine, is a warning to all patients about the dangers of getting unproven, unapproved stem cell therapies.

In this case, the clinic took fat and blood from the patient, put the samples through a centrifuge to concentrate the stem cells, mixed them together and then injected them into the back of the woman’s eyes. In each case they injected this mixture into both eyes.

Irreparable harm

Within days the women, who ranged in age from 72 to 88, began to experience severe side effects including bleeding in the eye, detached retinas, and vision loss. The women got expert treatment at specialist eye centers to try and undo the damage done by the clinic, but it was too late. They are now blind with little hope for regaining their eyesight.

In a news release Thomas Alibini, one of the lead authors of the study, says clinics like this prey on vulnerable people:

“There’s a lot of hope for stem cells, and these types of clinics appeal to patients desperate for care who hope that stem cells are going to be the answer, but in this case these women participated in a clinical enterprise that was off-the-charts dangerous.”

Warning signs

So what went wrong? The researchers say this clinic’s approach raised a number of “red flags”:

  • First there is almost no evidence that the fat/blood stem cell combination the clinic used could help repair the photoreceptor cells in the eye that are attacked in macular degeneration.
  • The clinic charged the women $5,000 for the procedure. Usually in FDA-approved trials the clinical trial sponsor will cover the cost of the therapy being tested.
  • Both eyes were injected at the same time. Most clinical trials would only treat one eye at a time and allow up to 30 days between patients to ensure the approach was safe.
  • Even though the treatment was listed on the clinicaltrials.gov website there is no evidence that this was part of a clinical trial, and certainly not one approved by the Food and Drug Administration (FDA) which regulates stem cell therapies.

As CIRM’s Abla Creasey told the San Francisco Chronicle’s Erin Allday, there is little evidence these fat stem cells are effective, or even safe, for eye conditions.

“There’s no doubt there are some stem cells in fat. As to whether they are the right cells to be put into the eye, that’s a different question. The misuse of stem cells in the wrong locations, using the wrong stem cells, is going to lead to bad outcomes.”

The study points out that not all projects listed on the Clinicaltrials.gov site are checked to make sure they are scientifically sound and have done the preclinical testing needed to reduce the likelihood they may endanger patients.

goldberg-jeffrey

Jeffrey Goldberg

Jeffrey Goldberg, a professor of Ophthalmology at Stanford and the co-author of the study, says this is a warning to all patients considering unproven stem cell therapies:

“There is a lot of very well-founded evidence for the positive potential of stem therapy for many human diseases, but there’s no excuse for not designing a trial properly and basing it on preclinical research.”

There are a number of resources available to people considering being part of a clinical trial including CIRM’s “So You Want to Participate in a Clinical Trial”  and the  website A Closer Look at Stem Cells , which is sponsored by the International Society for Stem Cell Research (ISSCR).

CIRM is currently funding two clinical trials aimed at helping people with vision loss. One is Dr. Mark Humayun’s research on macular degeneration – the same disease these women had – and the other is Dr. Henry Klassen’s research into retinitis pigmentosa. Both these projects have been approved by the FDA showing they have done all the testing required to try and ensure they are safe in people.

In the past this blog has been a vocal critic of the FDA and the lengthy and cumbersome approval process for stem cell clinical trials. We have, and still do, advocate for a more efficient process. But this study is a powerful reminder that we need safeguards to protect patients, that any therapy being tested in people needs to have undergone rigorous testing to reduce the likelihood it may endanger them.

These three women paid $5,000 for their treatment. But the final cost was far greater. We never want to see that happen to anyone ever again.

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

/ Kevin McCormack / Leave a comment

retinitis pigmentosas_1

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.

 

National honor for helping “the blind see”

/ Kevin McCormack / Leave a comment

Those of us fortunate to have good health take so many things for granted, not the least of which is our ability to see. But, according to the World Health Organization, there are 39 million people worldwide who are blind, and another 246 million who are visually impaired. Any therapy, any device, that can help change that is truly worthy of celebration.

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Dr. Mark Humayun: Photo courtesy USC

That’s why we are celebrating the news that Professor Mark Humayun has been awarded the National Medal of Technology and Innovation, the nation’s top technology honor, by President Obama.

Humayun, a researcher at USC’s Keck School of Medicine and a CIRM grantee, is being honored for his work in developing an artificial retina, one that enables people with a relatively rare kind of blindness to see again.

But we are also celebrating the potential of his work that we are funding that could help restore sight to millions of people suffering from the leading cause of blindness among the elderly. But we’ll get back to that in a minute.

First, let’s talk about the invention that has earned him this prestigious award. It’s called the Argus II and it can help people with retinitis pigmentosa, an inherited degenerative disease that slowly destroys a person’s vision. It affects around 100,000 Americans.

The Argus II uses a camera mounted on glasses that send signals to an electronic receiver that has been implanted inside the eye. The receiver then relays those signals through the optic nerve to the brain where they are interpreted as a visual image.

In a story posted on the USC website, USC President C. L. Max Nikias praised Humayun’s work:

“He dreamed the impossible: to help the blind see. With fearless imagination, bold leadership and biomedical expertise, he and his team made that dream come true with the world’s first artificial retina. USC is tremendously proud to be Professor Humayun’s academic home.”

At CIRM we are tremendously proud to be funding the clinical trial that Humayun and his team are running to find a stem cell therapy for age-related macular degeneration (AMD), the leading cause of vision loss in the world.  It’s estimated that by 2020 more than 6 million Americans will suffer from AMD.

Humayun’s team is using embryonic stem cells to produce the support cells, or RPE cells, needed to replace those lost in AMD. We recently produced this video that highlights this work, and other CIRM-funded work that targets vision loss.

In a statement released by the White House honoring all the winners, President Obama said:

“Science and technology are fundamental to solving some of our nation’s biggest challenges. The knowledge produced by these Americans today will carry our country’s legacy of innovation forward and continue to help countless others around the world. Their work is a testament to American ingenuity.”

Which is why we are honored to be partners with Humayun and his team in advancing this research and, hopefully, helping find a treatment for millions of people who dream of one day being able to see again.