6
QUESTION
ARE WE EVER GOING TO USE STEM CELLS? FOR WHAT? WHAT’S THE SCOOP?
Steven D. Schwartz, MD
Progress in the diagnosis and treatment of retinal disease is advancing at an unprecedented pace, yet there remains a significant societal burden of untreatable blindness resulting from disorders of the retina. This includes relatively common diseases, such as dry age-related macular degeneration, and less common conditions, such as retinitis pigmentosa and Stargardt disease. Stem cell-based strategies represent a promising therapeutic modality and catalyst for research. Stem cell-derived retinal pigment epithelium has already been transplanted into humans with central macular atrophy, and human photoreceptor transplantation is likely on the horizon. In addition, a variety of stem cell derivatives have shown promise as neuroprotective agents when transplanted into the eye.
Gene and cell therapy have the potential to prevent, halt, or reverse diseases of the retina in patients with currently incurable blinding diseases. Over the past 2 decades, major advances in our understanding of the pathobiologic basis of retinal diseases, coupled with growth of gene transfer and cell transplantation biotechnologies, have created optimism that previously blinding retinal conditions may be treatable. However, while gene therapies may be nearing approval, stem cell or regenerative cell therapies are likely at least 5 to 7 years away from regulatory approval at the time of this chapter.
In today’s world, however, patients are exposed to media and internet reports that are, at best, lacking nuance and detail and, at worst, intentionally deceptive. Unavoidably, every ophthalmologist has been or will be asked about stem cell therapies repeatedly. One of our roles as physicians and surgeons is to protect our patients from charlatans and scams that jeopardize safety for profit. My answer to each patient remains, “Stem cells are not approved and may be dangerous. You are not a candidate despite what you may hear or read online. Any use of unapproved therapies will likely preclude future treatment with well-studied therapies. If they ask you to pay, walk away.”
When health care providers ask, “What’s the scoop? Will we ever legitimately use stem cells for eye disease?” the appropriate response is, “Probably, but I’m an optimist.” A number of critical points deserve emphasis:
- There are currently no US Food and Drug Administration (FDA)–approved stem cell therapies.
- Risks of stem cell transplantation include, but are not limited to, loss of life, loss of eye, loss of vision, and severe systemic immune disease, among others.
- Despite the lack of proven, approved therapies, unproven, for-profit “stem cell therapies” are being sold to patients, jeopardizing both patient safety and scientific credibility.
Our mission as physicians and surgeons is to prevent and reduce human suffering and to protect patient safety. Impending blindness is certainly a source of suffering, and as such, creates a sense of urgency when the underlying condition is untreatable. This urgency coupled with the promise of stem cell biology and media interest in ongoing, legitimate clinical trials has led to a perfect storm wherein any number of problematic, dangerous, for-profit programs are leveraging desperation, poor public understanding, imprecise media coverage, and little or no regulatory involvement. In a perfect world, all clinical trials would be constructed with patient safety and respect for the scientific method as the guiding priority, and treatments would be guided by reliable data and high-level evidence. Unfortunately, the public’s insatiable desire for anything stem cell and irrational beliefs that stem cells cure everything have created a market for untested, unproven, unregulated, and often baseless “therapies.” “Often, these cells…are being used in practice on the basis of minimal clinical evidence of safety or efficacy, sometimes with the claim that they constitute revolutionary treatments for various conditions.”1 To illustrate the magnitude of this issue, in 2015, there were 570 clinics marketing stem cell treatment directly to consumers. Documented cases of harm, including iatrogenic blindness and pain necessitating bilateral enucleation, have prompted the American Academy of Ophthalmology (AAO) to ask, “How does the physician community distinguish legitimate clinical investigation from uncontrolled commercial use in the guise of investigation?”
Public misperceptions include:
- “Stem cells can cure anything.”
- “Stem cell therapy is no/low risk.”
- “If an institutional review board has approved it, it’s safe and probably going to be effective.”
- “If not FDA-regulated, it is FDA-approved.”
- “If it is listed on clinicaltrials.gov, it has been reviewed and approved by the National Institutes of Health.”
To help clarify or distinguish real science from the rest, the International Society for Stem Cell Research has pointed out the following warning signs:
- Same stem cells for multiple diseases
- Source of stem cells unclear
- No formal treatment protocol
- Claims based on patient testimonials
- Claims of no risk
Most importantly, I tell patients, “If you have to pay (to ‘participate in research’), stay away.” In fact, both the AAO and the International Society for Stem Cell Research agree that if the treatment costs money, it is likely illegitimate and may jeopardize patient safety in an irreversible manner. The AAO position as of 2018 is positive, “The potential of stem-cell based technologies hold promise for the repair, restoration and regeneration of dysfunctional cells in the eye, yet significant challenges remain. These treatments appear to offer hope to patients who may have limited options for recovery of vision, including patients with age-related macular degeneration, retinitis pigmentosa and Stargardt disease.”2 “The Academy believes that, in the interests of public health and patient safety, the FDA should continue to investigate unlicensed clinics that offer unapproved stem-cell therapy and to take appropriate regulatory actions. These treatments require further scientific evaluation to assure their safety and effectiveness to the public in well-conducted clinical trials under the aegis of the FDA.”2 As a translational researcher committed to the scientific method, patient safety, and innovation, I wholeheartedly support the AAO’s efforts to support the science, promote rigorous scientific method with societal impact, and protect patients as its priority. The context or framework in which not only science is conducted, but the environment in which it is interpreted and translated into clinical practice is, and should be, the purview of organized ophthalmology.
Summary
Stem cell-based therapies hold promise and may open pathways towards reduced suffering from visual loss. Unfortunately, progress toward these goals may be impeded by poorly designed, for-profit, dangerous “therapies” that are not based on rigorous science. Optimistically, with good teamwork, collaboration, and commitment to the scientific method, the legitimate use of stem cells in ophthalmology may be just around the corner.
Acknowledgment
Special recognition to Dr. David Parke and his team at the American Academy of Ophthalmology for their support and leadership.
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