Stem cell-derived retinal patch continues to show promising results two years post-implantation

Earlier this year we wrote about the promising results of a phase 1 clinical trial aimed at replacing the deteriorating cells in the retinas of people suffering from age-related macular degeneration- one of the leading causes of blindness worldwide for people over 50. Now there’s even more good news! Highlighted in a news story on the UC Santa Barbara (UCSB) website, researchers are continuing to make progress in their bid to secure approval from the Food and Drug Administration for the life-changing treatment.

Through the collaborative efforts of researchers at UCSB, University of Southern California and California Institute of Technology, a stem cell-derived implant using cells from a healthy donor was developed. The bioengineered implant, described as a scaffold, was then implanted under the retina of 16 participants. If the implant was to work, the new cells would then take up the functions of the old ones, and slow down or prevent further deterioration. In the best-case scenario, they could restore some lost vision.

The first sets of trials, funded by the California Institute for Regenerative Medicine (CIRM), concentrated on establishing the safety of the patch and collecting data on its effectiveness. Parting ways with old practices, the participants in the trial were given just two months of immunosuppressants whereas 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 implanted cells. The team found that after two years, the presence of the patch hadn’t triggered other conditions associated with implantation, such as the formation of new blood vessels or scar tissue that could cause a detachment of the retina.

Even more importantly, they found no sign of inflammation that indicated an immune response to the foreign cells even after the patient was taken off immunosuppressants two months post-implantation. “What really makes us excited is that there is some strong evidence to show that the cells are still there two years after implantation and they’re still functional,” said Mohamed Faynus, a graduate student researcher in the lab of stem cell biologist Dennis O. Clegg at UCSB.

Having passed the initial phase, the team of researchers now hopes to begin phase 2 of the trial. This time, they are aiming to more specifically assesses the effectiveness of the patch in participants. Looking even farther ahead, the Clegg Lab and colleagues are also exploring combining multiple cell types on the patch to treat patients at varying stages of the disease.

In addition, there have also been improvements made to extend the shelf life of the patch. “Cryopreservation of the therapy significantly extends the product’s shelf-life and allows us to ship the implant on demand all over the world, thus making it more accessible to patients across the globe,” said Britney Pennington, a research scientist in the Clegg Lab.

Creating a diverse group of future scientists

Students in CIRM’s Bridges program showing posters of their work

If you have read the headlines lately, you’ll know that the COVID-19 pandemic is having a huge impact on the shipping industry. Container vessels are forced to sit out at anchor for a week or more because there just aren’t enough dock workers to unload the boats. It’s a simple rule of economics, you can have all the demand you want but if you don’t have the people to help deliver on the supply side, you are in trouble.

The same is true in regenerative medicine. The field is expanding rapidly and that’s creating a rising demand for skilled workers to help keep up. That doesn’t just mean scientists, but also technicians and other skilled individuals who can ensure that our ability to manufacture and deliver these new therapies is not slowed down.

That’s one of the reasons why CIRM has been a big supporter of training programs ever since we were created by the voters of California when they approved Proposition 71. And now we are kick-starting those programs again to ensure the field has all the talented workers it needs.

Last week the CIRM Board approved 18 programs, investing more than $86 million, as part of the Agency’s Research Training Grants program. The goal of the program is to create a diverse group of scientists with the knowledge and skill to lead effective stem cell research programs.

The awards provide up to $5 million per institution, for a maximum of 20 institutions, over five years, to support the training of predoctoral graduate students, postdoctoral trainees, and/or clinical trainees.

This is a revival of an earlier Research Training program that ran from 2006-2016 and trained 940 “CIRM Scholars” including:

• 321 PhD students
• 453 Postdocs
• 166 MDs

These grants went to academic institutions from UC Davis in Sacramento to UC San Diego down south and everywhere in-between. A 2013 survey of the students found that most went on to careers in the industry.

  • 56% continued to further training
  • 14% advanced to an academic research faculty position
  • 10.5% advanced to a biotech/industry position
  • 12% advanced to a non-research position such as teaching, medical practice, or foundation/government work

The Research Training Grants go to:

AWARDINSTITUTIONTITLEAMOUNT
EDUC4-12751Cedars-SinaiCIRM Training Program in Translational Regenerative Medicine    $4,999,333
EDUC4-12752UC RiversideTRANSCEND – Training Program to Advance Interdisciplinary Stem Cell Research, Education, and Workforce Diversity    $4,993,115
EDUC4-12753UC Los AngelesUCLA Training Program in Stem Cell Biology    $5 million
EDUC4-12756University of Southern CaliforniaTraining Program Bridging Stem Cell Research with Clinical Applications in Regenerative Medicine    $5 million
EDUC4-12759UC Santa CruzCIRM Training Program in Systems Biology of Stem Cells    $4,913,271
EDUC4-12766Gladstone Inst.CIRM Regenerative Medicine Research Training Program    $5 million
EDUC4-12772City of HopeResearch Training Program in Stem Cell Biology and Regenerative Medicine    $4,860,989
EDUC4-12782StanfordCIRM Scholar Training Program    $4,974,073
EDUC4-12790UC BerkeleyTraining the Next Generation of Biologists and Engineers for Regenerative Medicine    $4,954,238
EDUC4-12792UC DavisCIRM Cell and Gene Therapy Training Program 2.0    $4,966,300
EDUC4-12802Children’s Hospital of Los AngelesCIRM Training Program for Stem Cell and Regenerative Medicine Research    $4,999,500
EDUC4-12804UC San DiegoInterdisciplinary Stem Cell Training Grant at UCSD III    $4,992,446
EDUC4-12811ScrippsTraining Scholars in Regenerative Medicine and Stem Cell Research    $4,931,353
EDUC4-12812UC San FranciscoScholars Research Training Program in Regenerative Medicine, Gene Therapy, and Stem Cell Research    $5 million
EDUC4-12813Sanford BurnhamA Multidisciplinary Stem Cell Training Program at Sanford Burnham Prebys Institute, A Critical Component of the La Jolla Mesa Educational Network    $4,915,671  
EDUC4-12821UC Santa BarbaraCIRM Training Program in Stem Cell Biology and Engineering    $1,924,497
EDUC4-12822UC IrvineCIRM Scholars Comprehensive Research Training Program  $5 million
EDUC4-12837Lundquist Institute for Biomedical InnovationStem Cell Training Program at the Lundquist Institute    $4,999,999

These are not the only awards we make to support training the next generation of scientists. We also have our SPARK and Bridges to Stem Cell Research programs. The SPARK awards are for high school students, and the Bridges program for graduate or Master’s level students.

CIRM-funded research aims to create a platform to test therapies for AMD

People with late stage age-related macular degeneration lose their central vision. So an image like the one on the left might appear to them as shown on the right.
Credit: University of California – Santa Barbara

Our vision is one of the most important senses that we use in our everyday lives. Whether its to help somebody perform complex surgeries or soak in a beautiful impressionist painting, a layer of cells in the back of the eye called the retinal pigment epithelium (RPE) provide support to photoreceptors (PRs), specialized cells that play an important role in our ability to process images. Unfortunately, as we get older, problems with this part of the eye can begin to develop.

Age-related macular degeneration (AMD) is an eye disease that causes severe vision impairment, resulting in the inability to read, drive, recognize faces, and blindness if left untreated.  It is the leading cause of vision loss in the U.S. and currently affects over 2 million Americans.  By the year 2050, it is projected that the number of affected individuals will more than double to over 5 million. The dysfunction and/or loss of RPE cells plays a critical role in the loss of PRs and hence the vision problems observed in AMD. One form of AMD for which there is no treatment is known as dry AMD (dAMD) and accounts for about 90% of all AMD cases. This version of dAMD is due to the inability of the RPE cells to heal.

CIRM-funded research at UC Santa Barbara aims to create a platform to test therapies for dAMD. Led by Dr. Peter Coffey and Dr. Lindsay Bailey-Steinitz, the team outlined two main objectives for this project. The first was to better understand what is occurring at the cellular level as the disease advances. The second was to develop a model that could be used to test therapeutics.

In a press release, Dr. Bailey-Steinitz discusses the importance of developing a disease model for dAMD.

“Part of the struggle of finding a treatment option is that we’ve not been able to really model the progression of the disease in cell culture or in animals.”

An overview of Dr. Coffey and Dr. Bailey-Steinitz’s experiment.
Credit: Lindsay Bailey-Steinitz

In dAMD, when RPE cells fail to repair themselves, they form a hole that gradually continues to expand. Dr. Bailey-Steinitz recreated this hole in the lab by culturing RPE cells on a plate with an electrode and then zapping them. This process created a hole very similar to the one that appears in dAMD. However, since the cells used in this experiment were younger cells, they were more prone to self healing. But the team found that 10 pulses of electricity over the course of 10 days prevented the younger cells from healing. The team also found that shocking the cells suppressed important genes involved in RPE cell function.

The team is planning future experiments with older cells since they demonstrate a decreased ability to heal.

In the same press release, Dr. Coffey highlights the potential impact of this work.

“”If we can improve this setup, then we’ve got a therapeutic testbed for AMD.”

CIRM has also funded a separate clinical trial for dAMD conducted by Dr. Mark Humayun at the University of Southern California.

The full results of this study were published in PLOS ONE.

Why having a wrinkled brain is a good thing

Brain_01

We normally associate wrinkles with aging, such as wrinkled skin. But there’s one organ that is wrinkled right from the time we are born. It’s our brain. And new research shows those wrinkles are not a sign of age but are, in fact, a sign of just how large and complex our brains are.

The wrinkles, according to U.C. Santa Barbara (UCSB) postdoctoral scholar Eyal Karzbrun, are vital to our development because they create a greater surface area giving our neurons, or brain nerve cells, more space to create connections and deliver information.

In an article in UCSB’s Daily Nexus, Karzbrun says while our knowledge of the brain is increasing there are still many things we don’t understand:

“The brain is a complex organ whose organization is essential to its function. Yet it is ‘assembled by itself’. How this assembly takes place and what physics come into play is fundamental to our understanding of the brain.”

Eyal Karzbrun

Eyal Karzbrun: Photo courtesy UCSB

Karzbrun used stem cells to create 3D clusters of brain cells, to better understand how they organize themselves. He said brains are like computers in the way they rely on surface area to process information.

“In order to be computationally strong and quick, what your brain does is take a lot of surface area and put it in a small volume. The cerebral cortex, which occupies most of the volume in your brain, has a unique architecture in which neurons are layered on the outer surface of the brain, and the bulk of the brain is composed of axons, [or] biological wire which interconnect the neurons.”

Karzbrun says gaining a deeper understanding of how the brain is formed, and why it takes the shape it does, may help us develop new approaches to treating problems in the brain.

 

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

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.