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."
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
The first thing Jeroen Perk saw after he partially regained his sight nearly a decade ago was the outline of his guide dog Pedro.
“There was a white floor, and the dog was black,” recalls Perk, a 43-year-old investigator for the Dutch customs service. “I was crying. It was a very nice moment.”
Perk was diagnosed with retinitis pigmentosa as a child and had been blind since early adulthood. He has been able to use the implant placed into his retina in 2013 to help identify street crossings, and even ski and pursue archery. A video posted by the company that designed and manufactured the device indicates he’s a good shot.
Less black-and-white has been the journey Perk and others have been on after they were implanted with the Argus II, a second-generation device created by a Los Angeles-based company called Second Sight Medical Devices.
The Argus II uses the implant and a video camera embedded in a special pair of glasses to provide limited vision to those with retinitis pigmentosa, a genetic disease that causes cells in the retina to deteriorate. The camera feeds information to the implant, which sends electrical impulses into the retina to recapitulate what the camera sees. The impulses appear in the Argus II as a 60-pixel grid of blacks, grays and whites in the user’s eye that can render rough outlines of objects and their motion.
Smartphone and computer manufacturers typically stop issuing software upgrades to their devices after two or three years, eventually rendering them bricks. But is the smartphone approach acceptable for a device that helps restore the most crucial sense a human being possesses?
Ross Doerr, a retired disability rights attorney in Maine who received an Argus II in 2019, describes the field of vision as the equivalent of an index card held at arm’s length. Perk often brings objects close to his face to decipher them. Moreover, users must swivel their heads to take in visual data; moving their eyeballs does not work.
Despite its limitations, the Argus II beats the alternative. Perk no longer relies on his guide dog. Doerr was uplifted when he was able to see the outlines of Christmas trees at a holiday show.
“The fairy godmother department sort of reaches out and taps you on the shoulder once in a while,” Doerr says of his implant, which came about purely by chance. A surgeon treating his cataracts was partnered with the son of another surgeon who was implanting the devices, and he was referred.
Doerr had no reason to believe the shower of fairy dust wouldn’t continue. Second Sight held out promises that the Argus II recipients’ vision would gradually improve through upgrades to much higher pixel densities. The ability to recognize individual faces was even touted as a possibility. In the winter of 2020, Doerr was preparing to travel across the U.S. to Second Sight’s headquarters to receive an upgrade. But then COVID-19 descended, and the trip was canceled.
The pandemic also hit Second Sight’s bottom line. Doerr found out about its tribulations only from one of the company’s vision therapists, who told him the entire department was being laid off. Second Sight cut nearly 80% of its workforce in March 2020 and announced it would wind down operations.
Ross Doerr has mostly stopped using his Argus II, the result of combination of fear of losing its assistance from wear and tear and disdain for the company that brought it to market.
Second Sight’s implosion left some 350 Argus recipients in the metaphorical dark about what to do if their implants failed. Skeleton staff seem to have rarely responded to queries from their customers, at least based on the experiences of Perk and Doerr. And some recipients have unfortunately returned to the actual dark as well, as reports have surfaced of Argus II failures due to aging or worn-down parts.
Product support for complex products is remarkably uneven. Although the iconic Ford Mustang ceased production in the late 1960s, its parts market is so robust that it’s theoretically possible to assemble a new vehicle from recently crafted components. Conversely, smartphone and computer manufacturers typically stop issuing software upgrades to their devices after two or three years, eventually rendering them bricks. Consumers have accepted both extremes.
But is the smartphone approach acceptable for a device that helps restore the most crucial sense a human being possesses?
Margaret McLean, a senior fellow at the Markkula Center for Applied Ethics at Santa Clara University in California, notes companies like Second Sight have a greater obligation for product support than other consumer product ventures.
“In this particular case, you have a great deal of risk that is involved in using this device, the implant, and the after care of this device,” she says. “You cannot, like with your car, decide that ‘I don’t like my Mustang anymore,’ and go out and buy a Corvette.”
And, whether the Argus II implant works or not, its physical presence can impact critical medical decisions. Doerr’s doctor wanted him to undergo an MRI to assist in diagnosing attacks of vertigo. But the physician was concerned his implant might interfere. With the latest available manufacturer advisories on his implant nearly a decade old, the procedure was held up. Doerr spent months importuning Second Sight through phone calls, emails and Facebook postings to learn if his implant was contraindicated with MRIs, which he never received. Although the cause of his vertigo was found without an MRI, Doerr was hardly assured.
“Put that into context for a minute. I get into a serious car accident. I end up in the emergency room, and I have a tag saying I have an implanted medical device,” he says. “You can’t do an MRI until you get the proper information from the company. Who’s going to answer the phone?”
Second Sight’s management did answer the call to revamp its business. It netted nearly $78 million through a private stock placement and an initial public offering last year. At the end of 2021, Second Sight had nearly $70 million in cash on hand, according to a recent filing with the Securities and Exchange Commission.
And while the Argus II is still touted at length on Second Sight’s home page, it appears little of its corporate coffers are earmarked toward its support. These days, the company is focused on obtaining federal approvals for Orion, a new implant that would go directly into the recipient’s brain and could be used to remedy blindness from a variety of causes. It obtained a $6.4 million grant from the National Institutes of Health in May 2021 to help develop Orion.
Presented with a list of written questions by email, Second Sight’s spokesperson, Dave Gentry of the investor relations firm Red Chip Companies, copied a subordinate with an abrupt message to “please handle.” That was the only response from a company representative. A call to Second Sight acting chief executive officer Scott Dunbar went unreturned.
Whether or not the Orion succeeds remains to be seen. The company’s SEC filings suggest a viable and FDA-approved device is years away, and that operational losses are expected for the “foreseeable future.” Second Sight reported zero revenue in 2020 or 2021.
Moreover, the experiences of the Argus II recipients could color the reception of future Second Sight products. Doerr notes that his insurer paid nearly $500,000 to implant his device and for training on how to use it.
“What’s the insurance industry going to say the next time this crops up?” Doerr asks, noting that the company’s reputation is “completely shot” with the recipients of its implants.
Perk, who made speeches to praise the Argus II and is still featured in a video on the Second Sight website, says he also no longer supports the company.
Jeroen Perk, an investigator for the Dutch customs service, cried for joy after partially regaining his sight, but he no longer trusts Second Sight, the company that provided his implant.
Nevertheless, Perk remains highly reliant on the technology. When he dropped an external component of his device in late 2020 and it broke, Perk briefly debated whether to remain blind or find a way to get his Argus II working again. Three months later, he was able to revive it by crowdsourcing parts, primarily from surgeons with spare components or other Argus II recipients who no longer use their devices. Perk now has several spare parts in reserve in case of future breakdowns.
Despite the frantic efforts to retain what little sight he has, Perk has no regrets about having the device implanted. And while he no longer trusts Second Sight, he is looking forward to possibly obtaining more advanced implants from companies in the Netherlands and Australia working on their own products.
Doerr suggests that biotech firms whose implants are distributed globally be bound to some sort of international treaty requiring them to service their products in perpetuity. Such treaties are still applied to the salvage rights for ships that sunk centuries ago, he notes.
“I think that in a global tech economy, that would be a good thing,” says McLean, the fellow at Santa Clara, “but I am not optimistic about it in the near term. Business incentives push toward return on share to stockholders, not to patients and other stakeholders. We likely need to rely on some combination of corporately responsibility…and [international] government regulation. It’s tough—the Paris Climate Accord implementation at a slow walk comes to mind.”
Unlike Perk, Doerr has mostly stopped using his Argus II, the result of combination of fear of losing its assistance from wear and tear and disdain for the company that brought it to market. At 70, Doerr says he does not have the time or energy to hold the company more accountable. And with Second Sight having gone through a considerable corporate reorganization, Doerr believes a lawsuit to compel it to better serve its Argus recipients would be nothing but an extremely costly longshot.
“It’s corporate America at its best,” he observes.
Lori Tipton's life was a cascade of trauma that even a soap opera would not dare inflict upon a character: a mentally unstable family; a brother who died of a drug overdose; the shocking discovery of the bodies of two persons her mother had killed before turning the gun on herself; the devastation of Hurricane Katrina that savaged her hometown of New Orleans; being raped by someone she trusted; and having an abortion. She suffered from severe PTSD.
“My life was filled with anxiety and hypervigilance,” she says. “I was constantly afraid and had mood swings, panic attacks, insomnia, intrusive thoughts and suicidal ideation. I tried to take my life more than once.” She was fortunate to be able to access multiple mental health services, “And while at times some of these modalities would relieve the symptoms, nothing really lasted and nothing really address the core trauma.”
Then in 2018 Tipton enrolled in a clinical trial that combined intense sessions of psychotherapy with limited use of Methylenedioxymethamphetamine, or MDMA, a drug classified as a psychedelic and commonly known as ecstasy or Molly. The regimen was arduous; 1-2 hour preparation sessions, three sessions where MDMA was used, which lasted 6-8 hours, and lengthy sessions afterward to process and integrate the experiences. Two therapists were with her every moment of the three-month program that totaled more than 40 hours.
“It was clear to me that [the therapists] weren't going to heal me, that I was going to have to do the work for myself, but that they were there to completely support my process,” she says. “But the effects of MDMA were really undeniable for me. I felt embodied in a way that I hadn't in years. PTSD had robbed me of the ability to feel safe in my own body.”
Tipton doesn’t think the therapy completely cured her PTSD. “But when I completed the trial in 2018, I no longer qualified for the diagnosis, and I still don't qualify for the diagnosis today,” she told an April workshop on psychedelics as mental health treatment by the National Academies of Sciences, Engineering and Medicine, or NASEM.
Rick Doblin has been a catalyst behind much of the contemporary research into psychedelics. Prior to the DEA clamp down, the Boston psychotherapist had seen that MDMA and other psychedelics could benefit some of his patients where other measures had failed. He immediately organized efforts to question the drug rescheduling but to little avail. In 1986, he created the nonprofit Multidisciplinary Association for Psychedelic Studies (MAPS), which slowly laid the scientific foundation for clinical trials, including the one that Tipton joined, using psychedelics to treat mental health conditions.
Now, only slowly, have researchers been able to explore the power of these drugs to treat a broad spectrum of severely debilitating mental health conditions, including trauma, depression, and PTSD, where other available treatments proved inadequate.
“Psychedelic psychotherapy is an attempt to go after the root causes of the problems with just a relatively few administrations, as contrasted to most of the psychiatric drugs used today that are mostly just reducing symptoms and are meant to be taken on a daily basis,” Doblin said in a 2019 TED Talk. Most of these drugs can have broad effect but “some are probably more effective than others for certain conditions,” he added in a recent interview with Leaps.org. Comparative head-to-head studies of psychedelic therapies simply have not been conducted.
Their mechanisms of action are poorly understood and can vary between drugs, but it is generally believed that psychedelics change the activity of neurons so that the brain processes information differently, says Katrin Preller, a neuropsychologist at the University of Zurich. A recent important study in Nature Medicine by Richard Daws and colleagues used functional magnetic resonance imaging (fMRI) of the brain and found that “functional networks became more functionally interconnected and flexible after psilocybin treatment…implying that psilocybin's antidepressant action may depend on a global increase in brain network integration.”
Rosalind Watts, a clinical investigator at the Imperial College in London, believes there is “an overestimation of the importance of the drug and an underestimation of the importance of the [therapeutic] context” in psychedelic research. “It is unethical to provide the drug without the other,” she says. Doblin notes that “psychotherapy outcomes research demonstrates that the therapeutic alliance between the therapist and the patients is the single most predictive factor of outcomes. [It is] trust and the sense of safety, the willingness to go into difficult spaces” that makes clinical breakthroughs possible with the drug.
Excitement and Challenges
Recurrent themes expressed at the NASEM workshop were exciting glimpses of the potential for psychedelics to treat mental health conditions combined with the challenges of realizing those potentials. A recent review paper found evidence that using psychedelics can help with treating a variety of common mental illnesses, but the paper could identify only 14 clinical trials of classic psychedelics published since 1991. Much of the reason is that the drugs are not patentable and so the pharmaceutical industry has no interest in investing in expensive clinical trials to bring them to market. MAPS has raised about $135 million over its 36-year history to conduct such research, says Doblin, the vast majority of it from individual donors and none from foundations.
The workshop participants’ views also were colored by the history of drug crackdowns and a fear that research might easily be shut down in the future. There was great concern that use of psychedelics should be confined to clinical trials with high safety and ethical standards, instead of doctors and patients experimenting on their own. “We need to get it right this time,” says Charles Grob, a psychiatrist at the UCLA School of Medicine. But restricting access to psychedelics will become even more difficult now that Oregon and several cities have acted to decriminalize possession and use of many of these drugs.
The experience with ketamine also troubled Grob. He is hoping to “mitigate the rush of rapid commercialization” that occurred with that drug. Ketamine technically is not a psychedelic though it does share some of their potentially euphoric properties. In 2019, soon after the FDA approved a form of ketamine with a limited label indication to treat depression, for profit clinics sprang up promoting off label use of the drug for psychiatric conditions where there was little clinical evidence of efficacy. He fears the same thing will happen when true psychedelics are made available.
If these therapies are approved, access to them is likely to be a problem. The drugs themselves are cheap but the accompanying therapy is not, and there is a shortage of trained psychotherapists. Mental health services often are not adequately covered by health insurance, while the poor and people of color suffer additional burdens of inadequate access. Doblin is committed to health care equity by training additional providers and by investigating whether some of the preparatory and integration sessions might be handled in a group setting. He says it is important that the legal aspects of psychedelics also be addressed so that patients “don't have to go underground” in order to receive this care.