Researchers Are Testing a New Stem Cell Therapy in the Hopes of Saving Millions from Blindness
NIH researchers in Kapil Bharti's lab work toward the development of induced pluripotent stem cells to treat dry age-related macular degeneration.
Of all the infirmities of old age, failing sight is among the cruelest. It can mean the end not only of independence, but of a whole spectrum of joys—from gazing at a sunset or a grandchild's face to reading a novel or watching TV.
The Phase 1 trial will likely run through 2022, followed by a larger Phase 2 trial that could last another two or three years.
The leading cause of vision loss in people over 55 is age-related macular degeneration, or AMD, which afflicts an estimated 11 million Americans. As photoreceptors in the macula (the central part of the retina) die off, patients experience increasingly severe blurring, dimming, distortions, and blank spots in one or both eyes.
The disorder comes in two varieties, "wet" and "dry," both driven by a complex interaction of genetic, environmental, and lifestyle factors. It begins when deposits of cellular debris accumulate beneath the retinal pigment epithelium (RPE)—a layer of cells that nourish and remove waste products from the photoreceptors above them. In wet AMD, this process triggers the growth of abnormal, leaky blood vessels that damage the photoreceptors. In dry AMD, which accounts for 80 to 90 percent of cases, RPE cells atrophy, causing photoreceptors to wither away. Wet AMD can be controlled in about a quarter of patients, usually by injections of medication into the eye. For dry AMD, no effective remedy exists.
Stem Cells: Promise and Perils
Over the past decade, stem cell therapy has been widely touted as a potential treatment for AMD. The idea is to augment a patient's ailing RPE cells with healthy ones grown in the lab. A few small clinical trials have shown promising results. In a study published in 2018, for example, a University of Southern California team cultivated RPE tissue from embryonic stem cells on a plastic matrix and transplanted it into the retinas of four patients with advanced dry AMD. Because the trial was designed to test safety rather than efficacy, lead researcher Amir Kashani told a reporter, "we didn't expect that replacing RPE cells would return a significant amount of vision." Yet acuity improved substantially in one recipient, and the others regained their lost ability to focus on an object.
Therapies based on embryonic stem cells, however, have two serious drawbacks: Using fetal cell lines raises ethical issues, and such treatments require the patient to take immunosuppressant drugs (which can cause health problems of their own) to prevent rejection. That's why some experts favor a different approach—one based on induced pluripotent stem cells (iPSCs). Such cells, first produced in 2006, are made by returning adult cells to an undifferentiated state, and then using chemicals to reprogram them as desired. Treatments grown from a patient's own tissues could sidestep both hurdles associated with embryonic cells.
At least hypothetically. Today, the only stem cell therapies approved by the U.S. Food and Drug Administration (FDA) are umbilical cord-derived products for various blood and immune disorders. Although scientists are probing the use of embryonic stem cells or iPSCs for conditions ranging from diabetes to Parkinson's disease, such applications remain experimental—or fraudulent, as a growing number of patients treated at unlicensed "stem cell clinics" have painfully learned. (Some have gone blind after receiving bogus AMD therapies at those facilities.)
Last December, researchers at the National Eye Institute in Bethesda, Maryland, began enrolling patients with dry AMD in the country's first clinical trial using tissue grown from the patients' own stem cells. Led by biologist Kapil Bharti, the team intends to implant custom-made RPE cells in 12 recipients. If the effort pans out, it could someday save the sight of countless oldsters.
That, however, is what's technically referred to as a very big "if."
The First Steps
Bharti's trial is not the first in the world to use patient-derived iPSCs to treat age-related macular degeneration. In 2013, Japanese researchers implanted such cells into the eyes of a 77-year-old woman with wet AMD; after a year, her vision had stabilized, and she no longer needed injections to keep abnormal blood vessels from forming. A second patient was scheduled for surgery—but the procedure was canceled after the lab-grown RPE cells showed signs of worrisome mutations. That incident illustrates one potential problem with using stem cells: Under some circumstances, the cells or the tissue they form could turn cancerous.
"The knowledge and expertise we're gaining can be applied to many other iPSC-based therapies."
Bharti and his colleagues have gone to great lengths to avoid such outcomes. "Our process is significantly different," he told me in a phone interview. His team begins with patients' blood stem cells, which appear to be more genomically stable than the skin cells that the Japanese group used. After converting the blood cells to RPE stem cells, his team cultures them in a single layer on a biodegradable scaffold, which helps them grow in an orderly manner. "We think this material gives us a big advantage," Bharti says. The team uses a machine-learning algorithm to identify optimal cell structure and ensure quality control.
It takes about six months for a patch of iPSCs to become viable RPE cells. When they're ready, a surgeon uses a specially-designed tool to insert the tiny structure into the retina. Within days, the scaffold melts away, enabling the transplanted RPE cells to integrate fully into their new environment. Bharti's team initially tested their method on rats and pigs with eye damage mimicking AMD. The study, published in January 2019 in Science Translational Medicine, found that at ten weeks, the implanted RPE cells continued to function normally and protected neighboring photoreceptors from further deterioration. No trace of mutagenesis appeared.
Encouraged by these results, Bharti began recruiting human subjects. The Phase 1 trial will likely run through 2022, followed by a larger Phase 2 trial that could last another two or three years. FDA approval would require an even larger Phase 3 trial, with a decision expected sometime between 2025 and 2028—that is, if nothing untoward happens before then. One unknown (among many) is whether implanted cells can thrive indefinitely under the biochemically hostile conditions of an eye with AMD.
"Most people don't have a sense of just how long it takes to get something like this to work, and how many failures—even disasters—there are along the way," says Marco Zarbin, professor and chair of Ophthalmology and visual science at Rutgers New Jersey Medical School and co-editor of the book Cell-Based Therapy for Degenerative Retinal Diseases. "The first kidney transplant was done in 1933. But the first successful kidney transplant was in 1954. That gives you a sense of the time frame. We're really taking the very first steps in this direction."
Looking Ahead
Even if Bharti's method proves safe and effective, there's the question of its practicality. "My sense is that using induced pluripotent stem cells to treat the patient from whom they're derived is a very expensive undertaking," Zarbin observes. "So you'd have to have a very dramatic clinical benefit to justify that cost."
Bharti concedes that the price of iPSC therapy is likely to be high, given that each "dose" is formulated for a single individual, requires months to manufacture, and must be administered via microsurgery. Still, he expects economies of scale and production to emerge with time. "We're working on automating several steps of the process," he explains. "When that kicks in, a technician will be able to make products for 10 or 20 people at once, so the cost will drop proportionately."
Meanwhile, other researchers are pressing ahead with therapies for AMD using embryonic stem cells, which could be mass-produced to treat any patient who needs them. But should that approach eventually win FDA approval, Bharti believes there will still be room for a technique that requires neither fetal cell lines nor immunosuppression.
And not only for eye ailments. "The knowledge and expertise we're gaining can be applied to many other iPSC-based therapies," says the scientist, who is currently consulting with several companies that are developing such treatments. "I'm hopeful that we can leverage these approaches for a wide range of applications, whether it's for vision or across the body."
NEI launches iPS cell therapy trial for dry AMD
A COVID-19 moonshot program challenged chemists around the world to submit ideas for how best to design a drug to target the virus.
By mid-March, Alpha Lee was growing restless. A pioneer of AI-driven drug discovery, Lee leads a team of researchers at the University of Cambridge, but his lab had been closed amidst the government-initiated lockdowns spreading inexorably across Europe.
If the Moonshot proves successful, they hope it could serve as a future benchmark for finding new medicines for chronic diseases.
Having spoken to his collaborators across the globe – many of whom were seeing their own experiments and research projects postponed indefinitely due to the pandemic – he noticed a similar sense of frustration and helplessness in the face of COVID-19.
While there was talk of finding a novel treatment for the virus, Lee was well aware the process was likely to be long and laborious. Traditional methods of drug discovery risked suffering the same fate as the efforts to find a cure for SARS in the early 2000, which took years and were ultimately abandoned long before a drug ever reached the market.
To avoid such an outcome, Lee was convinced that global collaboration was required. Together with a collection of scientists in the UK, US and Israel, he launched the 'COVID Moonshot' – a project which encouraged chemists worldwide to share their ideas for potential drug designs. If the Moonshot proves successful, they hope it could serve as a future benchmark for finding new medicines for chronic diseases.
Solving a Complex Jigsaw
In February, ShanghaiTech University published the first detailed snapshots of the SARS-CoV-2 coronavirus's proteins using a technique called X-ray crystallography. In particular, they revealed a high-resolution profile of the virus's main protease – the part of its structure that enables it to replicate inside a host – and the main drug target. The images were tantalizing.
"We could see all the tiny pieces sitting in the structure like pieces of a jigsaw," said Lee. "All we needed was for someone to come up with the best idea of joining these pieces together with a drug. Then you'd be left with a strong molecule which sits in the protease, and stops it from working, killing the virus in the process."
Normally, ideas for how best to design such a drug would be kept as carefully guarded secrets within individual labs and companies due to their potential value. But as a result, the steady process of trial and error to reach an optimum design can take years to come to fruition.
However, given the scale of the global emergency, Lee felt that the scientific community would be open to collective brainstorming on a mass scale. "Big Pharma usually wouldn't necessarily do this, but time is of the essence here," he said. "It was a case of, 'Let's just rethink every drug discovery stage to see -- ok, how can we go as fast as we can?'"
On March 13, he launched the COVID moonshot, calling for chemists around the globe to come up with the most creative ideas they could think of, on their laptops at home. No design was too weird or wacky to be considered, and crucially nothing would be patented. The entire project would be done on a not-for-profit basis, meaning that any drug that makes it to market will have been created simply for the good of humanity.
It caught fire: Within just two weeks, more than 2,300 potential drug designs had been submitted. By the middle of July, over 10,000 had been received from scientists around the globe.
The Road Toward Clinical Trials
With so many designs to choose from, the team has been attempting to whittle them down to a shortlist of the most promising. Computational drug discovery experts at Diamond and the Weizmann Institute of Science in Rehovot, Israel, have enabled the Moonshot team to develop algorithms for predicting how quick and easy each design would be to make, and to predict how well each proposed drug might bind to the virus in real life.
The latter is an approach known as computational covalent docking and has previously been used in cancer research. "This was becoming more popular even before COVID-19, with several covalent drugs approved by the FDA in recent years," said Nir London, professor of organic chemistry at the Weizmann Institute, and one of the Moonshot team members. "However, all of these were for oncology. A covalent drug against SARS-CoV-2 will certainly highlight covalent drug-discovery as a viable option."
Through this approach, the team have selected 850 compounds to date, which they have manufactured and tested in various preclinical trials already. Fifty of these compounds - which appear to be especially promising when it comes to killing the virus in a test tube – are now being optimized further.
Lee is hoping that at least one of these potential drugs will be shown to be effective in curing animals of COVID-19 within the next six months, a step that would allow the Moonshot team to reach out to potential pharmaceutical partners to test their compounds in humans.
Future Implications
If the project does succeed, some believe it could open the door to scientific crowdsourcing as a future means of generating novel medicine ideas for other diseases. Frank von Delft, professor of protein science and structural biology at the University of Oxford's Nuffield Department of Medicine, described it as a new form of 'citizen science.'
"There's a vast resource of expertise and imagination that is simply dying to be tapped into," he said.
Others are slightly more skeptical, pointing out that the uniqueness of the current crisis has meant that many scientists were willing to contribute ideas without expecting any future compensation in return. This meant that it was easy to circumvent the traditional hurdles that prevent large-scale global collaborations from happening – namely how to decide who will profit from the final product and who will hold the intellectual property (IP) rights.
"I think it is too early to judge if this is a viable model for future drug discovery," says London. "I am not sure that without the existential threat we would have seen so many contributions, and so many people and institutions willing to waive compensation and future royalties. Many scientists found themselves at home, frustrated that they don't have a way to contribute to the fight against COVID-19, and this project gave them an opportunity. Plus many can get behind the fact that this project has no associated IP and no one will get rich off of this effort. This breaks down a lot of the typical barriers and red-tape for wider collaboration."
"If a drug would sprout from one of these crowdsourced ideas, it would serve as a very powerful argument to consider this mode of drug discovery further in the future."
However the Moonshot team believes that if they can succeed, it will at the very least send a strong statement to policy makers and the scientific community that greater efforts should be made to make such large-scale collaborations more feasible.
"All across the scientific world, we've seen unprecedented adoption of open-science, collaboration and collegiality during this crisis, perhaps recognizing that only a coordinated global effort could address this global challenge," says London. "If a drug would sprout from one of these crowdsourced ideas, it would serve as a very powerful argument to consider this mode of drug discovery further in the future."
[An earlier version of this article was published on June 8th, 2020 as part of a standalone magazine called GOOD10: The Pandemic Issue. Produced as a partnership among LeapsMag, The Aspen Institute, and GOOD, the magazine is available for free online.]
World’s First “Augmented Reality” Contact Lens Aims to Revolutionize Much More Than Medicine
On the left, a picture of the Mojo lens smart contact; and a simulated image of a woman with low vision who is wearing the contact to highlight objects in her field of vision.
Imagine a world without screens. Instead of endlessly staring at your computer or craning your neck down to scroll through social media feeds and emails, information simply appears in front of your eyes when you need it and disappears when you don't.
"The vision is super clear...I was reading the poem with my eyes closed."
No more rude interruptions during dinner, no more bumping into people on the street while trying to follow GPS directions — just the information you want, when you need it, projected directly onto your visual field.
While this screenless future sounds like science fiction, it may soon be a reality thanks to the new Silicon Valley startup Mojo Vision, creator of the world's first smart contact lens. With a 14,000 pixel-per-inch display with eye-tracking, image stabilization, and a custom wireless radio, the Mojo smart lens bills itself the "smallest and densest dynamic display ever made." Unlike current augmented reality wearables such as Google Glass or ThirdEye, which project images onto a glass screen, the Mojo smart lens can project images directly onto the retina.
A current prototype displayed at the Consumer Electronics Show earlier this year in Las Vegas includes a tiny screen positioned right above the most sensitive area of the pupil. "[The Mojo lens] is a contact lens that essentially has wireless power and data transmission for a small micro LED projector that is placed over the center of the eye," explains David Hobbs, Director of Product Management at Mojo Vision. "[It] displays critical heads-up information when you need it and fades into the background when you're ready to continue on with your day."
Eventually, Mojo Visions' technology could replace our beloved smart devices but the first generation of the Mojo smart lens will be used to help the 2.2 billion people globally who suffer from vision impairment.
"If you think of the eye as a camera [for the visually impaired], the sensors are not working properly," explains Dr. Ashley Tuan, Vice President of Medical Devices at Mojo Vision and fellow of the American Academy of Optometry. "For this population, our lens can process the image so the contrast can be enhanced, we can make the image larger, magnify it so that low-vision people can see it or we can make it smaller so they can check their environment." In January of this year, the FDA granted Breakthrough Device Designation to Mojo, allowing them to have early and frequent discussions with the FDA about technical, safety and efficacy topics before clinical trials can be done and certification granted.
For now, Dr. Tuan is one of the few people who has actually worn the Mojo lens. "I put the contact lens on my eye. It was very comfortable like any contact lenses I've worn before," she describes. "The vision is super clear and then when I put on the accessories, suddenly I see Yoda in front of me and I see my vital signs. And then I have my colleague that prepared a beautiful poem that I loved when I was young [and] I was reading the poem with my eyes closed."
At the moment, there are several electronic glasses on the market like Acesight and Nueyes Pro that provide similar solutions for those suffering from visual impairment, but they are large, cumbersome, and highly visible. Mojo lens would be a discreet, more comfortable alternative that offers users more freedom of movement and independence.
"In the case of augmented-reality contact lenses, there could be an opportunity to improve the lives of people with low vision," says Dr. Thomas Steinemann, spokesperson for the American Academy of Ophthalmology and professor of ophthalmology at MetroHealth Medical Center in Cleveland. "There are existing tools for people currently living with low vision—such as digital apps, magnifiers, etc.— but something wearable could provide more flexibility and significantly more aid in day-to-day tasks."
As one of the first examples of "invisible computing," the potential applications of Mojo lens in the medical field are endless.
According to Dr. Tuan, the visually impaired often suffer from depression due to their lack of mobility and 70 percent of them are underemployed. "We hope that they can use this device to gain their mobility so they can get that social aspect back in their lives and then, eventually, employment," she explains. "That is our first and most important goal."
But helping those with low visual capabilities is only Mojo lens' first possible medical application; augmented reality is already being used in medicine and is poised to revolutionize the field in the coming decades. For example, Accuvein, a device that uses lasers to provide real-time images of veins, is widely used by nurses and doctors to help with the insertion of needles for IVs and blood tests.
According to the National Center for Biotechnology Information, augmentation of reality has been used in surgery for many years with surgeons using devices such as Google Glass to overlay critical information about their patients into their visual field. Using software like the Holographic Navigation Platform by Scopsis, surgeons can see a mixed-reality overlay that can "show you complicated tumor boundaries, assist with implant placements and guide you along anatomical pathways," its developers say.
However, according to Dr. Tuan, augmented reality headsets have drawbacks in the surgical setting. "The advantage of [Mojo lens] is you don't need to worry about sweating or that the headset or glasses will slide down to your nose," she explains "Also, our lens is designed so that it will understand your intent, so when you don't want the image overlay it will disappear, it will not block your visual field, and when you need it, it will come back at the right time."
As one of the first examples of "invisible computing," the potential applications of Mojo lens in the medical field are endless. Possibilities include live translation of sign language for deaf people; helping those with autism to read emotions; and improving doctors' bedside manner by allowing them to fully engage with patients without relying on a computer.
"[By] monitoring those blood vessels we can [track] chronic disease progression: high blood pressure, diabetes, and Alzheimer's."
Furthermore, the lens could be used to monitor health issues. "We have image sensors in the lens right now that point to the world but we can have a camera pointing inside of your eye to your retina," says Dr. Tuan, "[By] monitoring those blood vessels we can [track] chronic disease progression: high blood pressure, diabetes, and Alzheimer's."
For the moment, the future medical applications of the Mojo lens are still theoretical, but the team is confident they can eventually become a reality after going through the proper regulatory review. The company is still in the process of design, prototype and testing of the lens, so they don't know exactly when it will be available for use, but they anticipate shipping the first available products in the next couple of years. Once it does go to market, it will be available by prescription only for those with visual impairments, but the team's goal is to bring it to broader consumer markets pending regulatory clearance.
"We see that right now there's a unique opportunity here for Mojo lens and invisible computing to help to shape what the next decade of technology development looks like," explains David Hobbs. "We can use [the Mojo lens] to better serve us as opposed to us serving technology better."