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.

How a tiny patch is helping restore lasting vision

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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.”

Sometimes a cold stare is a good thing

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.

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.

CIRM Board Approves $19.7 Million in Awards for Translational Research Program

In addition to approving funding for breast cancer related brain metastases last week, the CIRM Board also approved an additional $19.7 million geared towards our translational research program. The goal of this program is to help promising projects complete the testing needed to begin talking to the US Food and Drug Administration (FDA) about holding a clinical trial.

Before getting into the details of each project, here is a table with a brief synopsis of the awards:

TRAN1 – 11532

Illustration of a healthy eye vs eye with AMD

$3.73 million was awarded to Dr. Mark Humayun at USC to develop a novel therapeutic product capable of slowing the progression of age-related macular degeneration (AMD).

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.  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.  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 is known as dry AMD (dAMD) and accounts for about 90% of all AMD cases.

The approach that Dr. Humayun is developing will use a biologic product produced by human embryonic stem cells (hESCs). This material will be injected into the eye of patients with early development of dAMD, supporting the survival of photoreceptors in the affected retina.

TRAN1 – 11579

Illustration depicting the role neuronal relays play in muscle sensation

$6.23 million was awarded to Dr. Mark Tuszynski at UCSD to develop a neural stem cell therapy for spinal cord injury (SCI).

According to data from the National Spinal Cord Injury Statistical Center, as of 2018, SCI affects an estimated 288,000 people in the United States alone, with about 17,700 new cases each year. There are currently no effective therapies for SCI. Many people suffer SCI in early adulthood, leading to life-long disability and suffering, extensive treatment needs and extremely high lifetime costs of health care.

The approach that Dr. Tuszynski is developing will use hESCs to create neural stem cells (NSCs).  These newly created NSCs would then be grafted at the site of injury of those with SCI.  In preclinical studies, the NSCs have been shown to support the formation of neuronal relays at the site of SCI.  The neuronal relays allow the sensory neurons in the brain to communicate with the motor neurons in the spinal cord to re-establish muscle control and movement.

TRAN1 – 11548

Graphic depicting the challenges of traumatic brain injury (TBI)

$4.83 million was awarded to Dr. Brian Cummings at UC Irvine to develop a neural stem cell therapy for traumatic brain injury (TBI).

TBI is caused by a bump, blow, or jolt to the head that disrupts the normal function of the brain, resulting in emotional, mental, movement, and memory problems. There are 1.7 million people in the United States experiencing a TBI that leads to hospitalization each year. Since there are no effective treatments, TBI is one of the most critical unmet medical needs based on the total number of those affected and on a cost basis.

The approach that Dr. Cummings is developing will also use hESCs to create NSCs.  These newly created NSCs would be integrated with injured tissue in patients and have the ability to turn into the three main cell types in the brain; neurons, astrocytes, and oligodendrocytes.  This would allow for TBI patients to potentially see improvements in issues related to memory, movement, and anxiety, increasing independence and lessening patient care needs.

TRAN1 – 11628

Illustration depicting the brain damage that occurs under hypoxic-ischemic conditions

$4.96 million was awarded to Dr. Evan Snyder at Sanford Burnham Prebys to develop a neural stem cell therapy for perinatal hypoxic-ischemic brain injury (HII).

HII occurs when there is a lack of oxygen flow to the brain.  A newborn infant’s body can compensate for brief periods of depleted oxygen, but if this lasts too long, brain tissue is destroyed, which can cause many issues such as developmental delay and motor impairment.  Current treatment for this condition is whole-body hypothermia (HT), which consists of significantly reducing body temperature to interrupt brain injury.  However, this is not very effective in severe cases of HII. 

The approach that Dr. Snyder is developing will use an established neural stem cell (NSC) line.   These NSCs would be injected and potentially used alongside HT treatment to increase protection from brain injury.

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

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 most popular Stem Cellar posts of 2018

The blog

You never know when you write something if people are going to read it. Sometimes you wonder if anyone is going to read it. So, it’s always fun, and educational, to look back at the end of the year and see which pieces got the most eyeballs.

It isn’t always the ones you think will draw the biggest audiences. Sometimes it is diseases that are considered “rare” (those affecting fewer than 200,000 people) that get the most attention.

Maybe it’s because those diseases have such a powerful online community which shares news, any news, about their condition of interest with everyone they know. Whatever the reason, we are always delighted to share encouraging news about research we are funding or encouraging research that someone else is funding.

That was certainly the case with the top two stories this year. Both were related to ALS or Lou Gehrig’s disease.  It’s a particularly nasty condition. People diagnosed with ALS have a life expectancy of just 2 to 5 years. So it’s probably not a big surprise that stories suggesting stem cells could expand that life span got a big reception.

Whatever the reason, we’re just happy to share hopeful news with everyone who comes to our blog.

And so, without further ado, here is the list of the most popular Stem Cellar Blog Posts for 2018.

All of us in the Communications team at CIRM consider it an honor and privilege to be able to work here and to meet many of the people behind these stories; the researchers and the patients and patient advocates. They are an extraordinary group of individuals who help remind us why we do this work and why it is important. We love our work and we hope you enjoy it too. We plan to be every bit as active and engaged in 2019.

Stem Cell Agency’s Diane Winokur hailed as Visionary

Diane and JT

CIRM Board member Diane Winokur with CIRM Board Chair Jonathan Thomas at FFB Awards dinner

Generally speaking, I am not a huge fan of gala dinners. It’s not that I don’t like seeing people who do remarkable things getting a well-deserved honor. It’s just that the dinners often go on too long and the food is usually not very good (hey, this is San Francisco, those things matter). But last night’s Foundation Fighting Blindness Visionary Awards in San Francisco was definitely an exception to that rule.

Academy of Sciences Grand Opening

Academy of Sciences in San Francisco

Now it may be that the awards were held in the spectacular Academy of Sciences building in Golden Gate Park, or that the food was delicious. But I think the real reason is that CIRM Board member Diane Winokur was one of those being honored. The other honoree was Dr. Jacque Duncan, an amazing physician at UC San Francisco who has dedicated her life to battling diseases of the retina. The whole event was deeply emotional, and truly inspiring.

Now, Diane is a remarkable woman in many respects. She’s the Board’s Patient Advocate member for ALS (better known as Lou Gehrig’s disease) and multiple sclerosis. But Diane also considers herself a Patient Advocate for all Californians and works hard to help advance the research that could help them. She has a personal connection to vision loss as well; one of her dear friends has lost his sight because of retinitis pigmentosa, and his daughter is losing hers because of the same disease.

Diane at podiumDiane highlighted the work that CIRM is doing to help battle vision destroying diseases; how we have invested more than $125 million in 25 different projects. She talked about the encouraging news from clinical trials we are funding targeting retinitis pigmentosa and dry age-related macular degeneration. Diane said:

“These stem cell clinical trials show that progress is being made. Not as fast as we would like, but as everyone here knows, good science takes time. As a patient advocate on the CIRM Board it’s my role to represent the patient, to be their voice in making decisions about what projects to fund.

Patients are at the heart of everything we do at CIRM, from deciding on funding issues to supporting clinical trials. That’s why I feel so honored to get this award. It comes from an organization, that is equally committed to doing all it can to help people in need, to putting the patient at the center of everything they do.”

It’s clear that patients really are at the heart of the work the Foundation Fighting Blindness (FFB) does. As the organizations CEO Benjamin Yerxa said:

“We support 77 labs in the US, often funding projects no one else would. We do this because we know it is necessary to advance the field. And we are going to keep doing this as best we can, as fast as we can, for as long as we can, because we know so many people are depending on us to help them.”

The other honoree, Jacque Duncan, said after attending many previous Visionary Award dinners and seeing the people being honored it was humbling to be in that company. She talked about the exciting progress being made in the field and the people who are making it possible.

“None of this happens by chance. The path to developing new treatments takes the passion of scientists and doctors, and the commitment of patients to raising the funds needed to do this research. One gala dinner at a time, one Vision Walk at a time. All of this creates community and a common purpose. I truly believe that because of this, tomorrow will be brighter than today.”

Perhaps it’s only appropriate to leave the last word to Diane, who ended her speech saying:

“The Nobel prize winning physicist Heinrich Rohrer once said that science means constantly walking a tightrope between blind faith and curiosity; between expertise and creativity; between bias and openness; between experience and epiphany; in short, between an old today and a new tomorrow.

I believe that working together, CIRM and the Foundation Fighting Blindness, we can create that new tomorrow.”

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

“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.

Stem Cell Patch Restores Vision in Patients with Age-Related Macular Degeneration

Stem cell-derived retinal pigmented epithelial cells. Cell borders are green and nuclei are red. (Photo Credit: Dennis Clegg, UCSB Center for Stem Cell Biology and Engineering)

Two UK patients suffering from vision loss caused by age-related macular degeneration (AMD) have regained their sight thanks to a stem cell-based retinal patch developed by researchers from UC Santa Barbara (UCSB). The preliminary results of this promising Phase 1 clinical study were published yesterday in the journal Nature Biotechnology.

AMD is one of the leading causes of blindness and affects over six million people around the world. The disease causes the blurring or complete loss of central vision because of damage to an area of the retina called the macula. There are different stages (early, intermediate, late) and forms of AMD (wet and dry). The most common form is dry AMD which occurs in 90% of patients and is characterized by a slow progression of the disease.

Patching Up Vision Loss

In the current study, UCSB researchers engineered a retinal patch from human embryonic stem cells. These stem cells were matured into a layer of cells at the back of the eye, called the retinal pigment epithelium (RPE), that are damaged in AMD patients. The RPE layer was placed on a synthetic patch that is implanted under the patient’s retina to replace the damaged cells and hopefully improve the patient’s vision.

The stem cell-based eyepatches are being implanted in patients with severe vision loss caused by the wet form of AMD in a Phase 1 clinical trial at the Moorfields Eye Hospital NHS Foundation Trust in London, England. The trial was initiated by the London Project to Cure Blindness, which was born from a collaboration between UCSB Professor Peter Coffey and Moorsfields retinal surgeon Lyndon da Cruz. Coffey is a CIRM grantee and credited a CIRM Research Leadership award as one of the grants that supported this current study.

The trial treated a total of 10 patients with the engineered patches and reported 12-month data for two of these patients (a woman in her 60s and a man in his 80s) in the Nature Biotech study. All patients were given local immunosuppression to prevent the rejection of the implanted retinal patches. The study reported “three serious adverse events” that required patients to be readmitted to the hospital, but all were successfully treated. 12-months after treatment, the two patients experienced a significant improvement in their vision and went from not being able to read at all to reading 60-80 words per minute using normal reading glasses.

Successfully Restoring Sight

Douglas Waters, the male patient reported on, was diagnosed with wet AMD in July 2015 and received the treatment in his right eye a few months later. He spoke about the remarkable improvement in his vision following the trial in a news release:

“In the months before the operation my sight was really poor, and I couldn’t see anything out of my right eye. I was struggling to see things clearly, even when up-close. After the surgery my eyesight improved to the point where I can now read the newspaper and help my wife out with the gardening. It’s brilliant what the team have done, and I feel so lucky to have been given my sight back.”

This treatment is “the first description of a complete engineered tissue that has been successfully used in this way.” It’s exciting not only that both patients had a dramatic improvement in their vision, but also that the engineered patches were successful at treating an advanced stage of AMD.

The team will continue to monitor the patients in this trial for the next five years to make sure that the treatment is safe and doesn’t cause tumors or other adverse effects. Peter Coffey highlighted the significance of this study and what it means for patients suffering from AMD in a UCSB news release:

Peter Coffey

“This study represents real progress in regenerative medicine and opens the door to new treatment options for people with age-related macular degeneration. We hope this will lead to an affordable ‘off-the-shelf’ therapy that could be made available to NHS patients within the next five years.”