Regenerative Patch Technologies

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.

Sometimes a cold stare is a good thing

/ Kevin McCormack / 6 Comments
A retina of a patient with macular degeneration. (Photo credit: Paul Parker/SPL)

Age-related macular degeneration (AMD) is the leading cause of vision loss and blindness in the elderly in the U.S. It’s estimated that some 11 million Americans could have some form of the disease, a number that is growing every year. So if you are going to develop a treatment for this condition, you need to make sure it can reach a lot of people easily. And that’s exactly what some CIRM-supported researchers are doing.

Let’s back up a little first. AMD is a degenerative condition where the macular, the small central portion of your retina, is slowly worn away. That’s crucial because the retina is the light-sensing nerve tissue at the back of your eye. At first you notice that your vision is getting blurry and it’s hard to read fine print or drive a car. As it progresses you develop dark, blurry areas in the center of your vision.

There are two kinds of AMD, a wet form and a dry form. The dry form is the most common, affecting 90% of patients. There is no cure and no effective treatment. But researchers at the University of Southern California (USC), the University of California Santa Barbara (UCSB) and a company called Regenerative Patch Technologies are developing a method that is looking promising.

They are using stem cells to grow retinal pigment epithelium (RPE) cells, the kind attacked by the disease, and putting them on a tiny synthetic scaffold which is then placed at the back of the eye. The hope is these RPE cells will help slow down the progression of the disease or even restore vision.

Early results from a CIRM-funded clinical trial are encouraging. 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.

So now the team are taking this approach one step further. In a study published in Scientific Reports, they say they have developed a way to cryopreserve or freeze this cell and scaffold structure.

In a news release, Dr. Dennis Clegg of UCSB, says the frozen implants are comparable to the non-frozen ones and this technique will extend shelf life and enable on-demand distribution to distant clinical sites, increasing the number of patients able to benefit from such treatments.

“It’s a major advance in the development of cell therapies using a sheet of cells, or a monolayer of cells, because you can freeze them as the final product and ship them all over the world.”

Cool.

Women who have changed, and are changing, the world

/ Kevin McCormack / Leave a comment

The problem with trying to write about something like Women’s History Month is where do you start? Even if you narrow it down to women in science the list is vast.

Marie Curie

I suppose you could always start with Maria Salomea Skłodowska who is better known as Marie Curie. She not only discovered radium and polonium, but she was also the first woman to win a Nobel Prize (in Physics). When she later won another Nobel (in Chemistry) she became the first person ever to win two Nobels and is still the only person ever to win in two different fields. Not a bad place to start.

Agnes Pockels

Or how about Agnes Pockels (1862–1935). Even as a child Agnes was fascinated by science but, in Germany at the time, women were not allowed to attend university. So, she depended on her younger brother to send her his physics textbooks when he was finished with them. Agnes studied at home while taking care of her elderly parents. Doing the dishes  Agnes noticed how oils and soaps could impact the surface tension of water. So, she invented a method of measuring that surface tension. She wrote a paper about her findings that was published in Nature, and went on to become a highly respected and honored pioneer in the field.

Jennifer Doudna (left) and Emmanuelle Charpentier: Photo courtesy Nature

Fast forward to today we could certainly do worse than profile the two women who won the 2020 Nobel Prize in Chemistry for their work with the gene-editing tool CRISPR-Cas9; Jennifer Doudna at the University of California, Berkeley, and Emmanuelle Charpentier at the Max Planck Unit for the Science of Pathogens in Berlin. Their pioneering work showed how you could use CRISPR  to make precise edits in genes, creating the possibility of using it to edit human genes to eliminate or cure diseases. In fact, some CIRM-funded research is already using this approach to try and cure sickle cell disease.

In awarding the Nobel to Charpentier and Doudna, Pernilla Wittung Stafshede, a biophysical chemist and member of the Nobel chemistry committee, said: “The ability to cut DNA where you want has revolutionized the life sciences. The ‘genetic scissors’ were discovered just eight years ago but have already benefited humankind greatly.”

Barbara McClintock: Photo courtesy Brittanica

Appropriately enough none of that work would have been possible without the pioneering work of another woman, Barbara McClintock. She dedicated her career to studying the genetics of corn and developed a technique that enabled her to identify individual chromosomes in different strains of corn.

At the time it was thought that genes were stable and were arranged in a linear fashion on chromosomes, like beads on a string. McClintock’s work showed that genes could be mobile, changing position and altering the work of other genes. It took a long time before the scientific world caught up with her and realized she was right. But in 1983 she was awarded the Nobel Prize in Medicine for her work.

Katherine Johnson at her desk at Langley Research Center: Photo courtesy NASA /AFP

Katherine Johnson is another brilliant mind whose recognition came later in life. But when it did, it made her a movie star. Kind of. Johnson was a mathematician, a “computer” in the parlance of the time. She did calculations by hand, enabling NASA to safely launch and recover astronauts in the early years of the space race.

Johnson and the other Black “computers” were segregated from their white colleagues until the last 1950’s, when signs dictating which restrooms and drinking fountains they could use were removed. She was so highly regarded that when John Glenn was preparing for the flight that would make him the first American to orbit the earth he asked for her to manually check the calculations a computer had made. He trusted her far more than any machine.

Johnson and her co-workers were overlooked until the 2016 movie “Hidden Figures” brought their story to life. She was also awarded the Presidential Medal of Freedom, America’s highest civilian honor, by President Obama.

There are so many extraordinary women scientists we could talk about who have made history. But we should also remind ourselves that we are surrounded by remarkable women right now, women who are making history in their own way, even if we don’t recognized it at the moment. Researchers that CIRM funds, Dr. Catriona Jamieson at UC San Diego, Dr. Jan Nolta at UC Davis, Dr. Jane Lebkowski with Regenerative Patch technologies and so many others. They’re all helping to change the world. We just don’t know it yet.

If you would like to learn about other women who have made extraordinary contributions to science you can read about them here and here and here.

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.

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.

 

 

Throwback Thursday: Progress to a Cure for Diseases of Blindness

/ Karen Ring / Leave a comment

Welcome back to our “Throwback Thursday” series on the Stem Cellar. Over the years, we’ve accumulated an arsenal of exciting stem cell stories about advances towards stem cell-based cures for serious diseases. This month we’re featuring stories about CIRM-funded clinical trials for blindness.

2017 has been an exciting year for two CIRM-funded clinical trials that are testing stem cell-based therapies for diseases of blindness. A company called Regenerative Patch Technologies (RPT) is transplanting a sheet of embryonic stem cell-derived retinal support cells into patients with the dry form of age-related macular degeneration, a disease that degrades the eye’s macula, the center of the retina that controls central vision. The other trial, sponsored by a company called jCyte, is using human retinal progenitor cells to treat retinitis pigmentosa, a rare genetic disease that destroys the light-sensing cells in the retina, causing tunnel vision and eventually blindness.

 

Both trials are in the early stages, testing the safety of their respective stem cell therapies. But the teams are hopeful that these treatments will stop the progression of or even restore some form of vision in patients. In the past few months, both RPT and jCyte have shared exciting news about the progress of these trials which are detailed below.

Macular Degeneration Trial Gets a New Investor

In April, RPT announced that they have a new funding partner to further develop their stem cell therapy for age-related macular degeneration (AMD). They are partnering with Japan’s Santen Pharmaceutical Company, which specializes in developing ophthalmology or eye therapies.

AMD is the leading cause of blindness in elderly people and is projected to affect almost 200 million people worldwide by 2020. There is no cure or treatment that can restore vision in AMD patients, but stem cell transplants offer a potential therapeutic option.

RPT believes that their newfound partnership with Santen will accelerate the development of their stem cell therapy and ultimately fulfill an unmet medical need. RPT’s co-founder, Dr. Dennis Clegg, commented in a CIRM news release, “the ability to partner with a global leader in ophthalmology like Santen is very exciting. Such a strong partnership will greatly accelerate RPT’s ability to develop our product safely and effectively.”

This promising relationship highlights CIRM’s efforts to partner our clinical programs with outside investors to boost their chance of success. It also shows confidence in the future success of RPT’s stem cell-based therapy for AMD.

Retinitis Pigmentosa Trial Advances to Phase 2 and Receives RMAT Status

In May, the US Food and Drug Administration (FDA) approved jCyte’s RP trial for Regenerative Medicine Advanced Therapy (RMAT) status, which could pave the way for accelerated approval of this stem cell therapy for patients with RP.

RMAT is a new status established under the 21st Century Cures Act – a law enacted by Congress in December of 2016 to address the need for a more efficient regulatory approval process for stem cell therapies that can treat serious or life-threatening diseases. Trial sponsors of RMAT designated therapies can meet with the FDA earlier in the trial process and are eligible for priority review and accelerated approval.

jCyte’s RMAT status is well deserved. Their Phase 1 trial was successful, proving the treatment was safe and well-tolerated in patients. More importantly, some of the patients revealed that their sight has improved following their stem cell transplant. We’ve shared the inspiring stories of two patients, Rosie Barrero and Kristin Macdonald, previously on the Stem Cellar.

Rosie Barrero

Kristin MacDonald

Both Rosie and Kristin were enrolled in the Phase 1 trial and received an injection of retinal progenitor cells in a single eye. Rosie said that she went from complete darkness to being able to see shapes, colors, and the faces of her family and friends. Kristin was the first patient treated in jCyte’s trial, and she said she is now more sensitive to light and can see shapes well enough to put on her own makeup.

Encouraged by these positive results, jCyte launched its Phase 2 trial in April with funding from CIRM. They will test the same stem cell therapy in a larger group of 70 patients and monitor their progress over the next year.

Progress to a Cure for Blindness

We know very well that scientific progress takes time, and unfortunately we don’t know when there will be a cure for blindness. However, with the advances that these two CIRM-funded trials have made in the past year, our confidence that these stem cell treatments will one day benefit patients with RP and AMD is growing.

I’ll leave you with an inspiring video of Rosie Barrero about her experience with RP and how participating in jCytes trial has changed her life. Her story is an important reminder of why CIRM exists and why supporting stem cell research in particular, and research in general, is vital for the future health of patients.

Related Links:

Creating partnerships to help get stem cell therapies over the finish line

/ Kevin McCormack / Leave a comment

Lewis, Clark, Sacagawea

Lewis & Clark & Sacagawea:

Trying to go it alone is never easy. Imagine how far Lewis would have got without Clark, or the two of them without Sacagawea. Would Batman have succeeded without Robin; Mickey without Minnie Mouse? Having a partner whose skills and expertise complements yours just makes things easier.

That’s why some recent news about two CIRM-funded companies running clinical trials was so encouraging.

Viacyte Gore

First ViaCyte, which is developing an implantable device to help people with type 1 diabetes, announced a collaborative research agreement with W. L. Gore & Associates, a global materials science company. On every level it seems like a natural fit.

ViaCyte has developed a way of maturing embryonic stem cells into an early form of the cells that produce insulin. They then insert those cells into a permeable device that can be implanted under the skin. Inside the device, the cells mature into insulin-producing cells. While ViaCyte has experience developing the cells, Gore has experience in the research, development and manufacturing of implantable devices.

Gore-tex-fabricWhat they hope to do is develop a kind of high-tech version of what Gore already does with its Gore-Tex fabrics. Gore-Tex keeps the rain out but allows your skin to breathe. To treat diabetes they need a device that keeps the immune system out, so it won’t attack the cells inside, but allows those cells to secrete insulin into the body.

As Edward Gunzel, Technical Leader for Gore PharmBIO Products, said in a news release, each side brings experience and expertise that complements the other:

“We have a proven track record of developing and commercializing innovative new materials and products to address challenging implantable medical device applications and solving difficult problems for biologics manufacturers.  Gore and ViaCyte began exploring a collaboration in 2016 with early encouraging progress leading to this agreement, and it was clear to us that teaming up with ViaCyte provided a synergistic opportunity for both companies.  We look forward to working with ViaCyte to develop novel implantable delivery technologies for cell therapies.”

AMD2

How macular degeneration destroys central vision

Then last week Regenerative Patch Technologies (RPT), which is running a CIRM-funded clinical trial targeting age-related macular degeneration (AMD), announced an investment from Santen Pharmaceutical, a Japanese company specializing in ophthalmology research and treatment.

The investment will help with the development of RPT’s therapy for AMD, a condition that affects millions of people around the world. It’s caused by the deterioration of the macula, the central portion of the retina which is responsible for our ability to focus, read, drive a car and see objects like faces in fine details.

RPE

RPT is using embryonic stem cells to produce the support cells, or RPE cells, needed to replace those lost in AMD. Because these cells exist in a thin sheet in the back of the eye, the company is assembling these sheets in the lab by growing the RPE cells on synthetic scaffolds. These sheets are then surgically implanted into the eye.

In a news release, RPT’s co-founder Dennis Clegg says partnerships like this are essential for small companies like RPT:

“The ability to partner with a global leader in ophthalmology like Santen is very exciting. Such a strong partnership will greatly accelerate RPT’s ability to develop our product safely and effectively.”

These partnerships are not just good news for those involved, they are encouraging for the field as a whole. When big companies like Gore and Santen are willing to invest their own money in a project it suggests growing confidence in the likelihood that this work will be successful, and that it will be profitable.

As the current blockbuster movie ‘Beauty and the Beast’ is proving; with the right partner you can not only make magic, you can also make a lot of money. For potential investors those are both wonderfully attractive qualities. We’re hoping these two new partnerships will help RPT and ViaCyte advance their research. And that these are just the first of many more to come.