Stem cell therapy's concept is deceptively simple: take cells from a donor and put them into a patient to treat a disease or injury. However, the reality falls far short of the dream.
Regenerative medicine makes use of cells, biomaterials, and molecules to fix structures in the body that do not function properly due to disease or injury.
What sets regenerative medicine apart from many traditional drugs is that the latter mostly treat symptoms, whereas the former aims to treat the root cause of a patient's condition by replacing lost cells or organs, or by fixing a faulty gene.
The allure of regenerative medicine promises to redefine medical treatment, putting stem cells and biocompatible materials center stage in this revolution. Many breakthroughs have been reported and hailed in scientific journals and the media over the years.
However, the number of regenerative medicine treatments in medical use today is disappointingly low, and a panel of commissioners criticizes this lack of progress in a report published last week in The Lancet.
In fact, according to Prof. Giulio Cossu - from the Division of Cell and Matrix Biology & Regenerative Medicine at the University of Manchester in the United Kingdom - and his fellow commissioners, only a handful of breakthroughs have made it to patients, and private clinics are cashing in on patients' desperate search for treatments by offering unproven therapies.
Why have so many promises of new therapies fallen short? And what will it take for society to benefit from the immense potential that regenerative medicine holds?
What is regenerative medicine?
The commissioners say in their report that regenerative medicine "aims to replace or repair human cells, or regenerate tissue or organs to restore normal function." The emphasis on "normal function" sets this approach to medical treatments apart from many commonly used drugs, which tend to treat symptoms but do not address the underlying causes.
"Cell therapies and regenerative medicine, with their potential to improve the health of patients, represent a structural shift in healthcare by focusing on the underlying causes of disease by repairing, replacing, or regenerating damaged cells in the body," the authors explain.
Regenerative medicine seeks to solve this by regenerating the islets of Langerhans, which allow the individual to make insulin. This would mean no more insulin injections and a return to normal sugar metabolism.
While the treatment of type 1 diabetes in this way is not yet a reality, there are some areas of regenerative medicine that are well established in medical practice.
The earliest form of cell therapy was the transfusion of blood, which is commonplace in most clinical settings nowadays.
Cell therapy using a patient's own cells is also used in cases of severe burn and scald injuries, when a patient does not have a sufficient amount of undamaged skin for skin graft treatment.
Here, skin cells are isolated from a small biopsy and expanded in a specialized laboratory. Millions of cells can be grown in a relatively short time and transplanted onto the burn wound to speed up healing.
But despite these successes and the fact that scientists around the world are furiously working on new therapies, regenerative medicine treatments have not entered mainstream medical practice in most areas of medicine.
According to the report in The Lancet, "the potential exists to substantially reduce the burden of disease for some common conditions (e.g., stroke, heart disease, progressive neurological conditions, autoimmune diseases, and trauma)."
And, "As well as increasing life expectancy, regenerative medicine therapies could greatly improve the health-related quality of life of many patients with chronic diseases."
So, what is holding back these developments?
From research to medical practice
An army of scientists from around the world is working on new regenerative medicine solutions to common diseases and injuries.
In the past year alone, Medical News Today reported on a chip technology that can change one cell type into another and heal entire organs, a new method of spray painting biomaterials onto damaged hearts using minimally invasive surgery, and a growth factor that might reverse osteoporosis.
Yet the list of approved cellular and gene therapy products on the Food and Drug Administration (FDA) website is surprisingly short: it has only 15 entries.
According to the authors of the report published in The Lancet:
"Cell therapy has produced clinically extraordinary results, having saved hundreds of thousands of lives [...] However, many cell therapies have had limited, variable, or transient efficacy."
The road from successful research to medical practice is long, because health authorities such as the FDA, who grant approval for a new therapy, must be satisfied that a new treatment is safe and works.
Regenerative medicine treatments tend to be very expensive because they often need special production facilities and highly skilled staff. With health budgets squeezed in many countries, high costs are a barrier to making such therapies a reality.
"Huge benefits might be reaped from regenerative medicine but at huge cost, and affordability might limit implementation, even if there is a good chance of cost savings down the line," the commissioners explain.
"While the market grows over the next few decades," the report's authors explain, "thinking of ways that regenerative medicine products can be made more affordable and cost-effective will be useful so that patients can benefit."
What is clear is that there is an enormous demand for regenerative medicine strategies to address common health problems, and that both small and big players in the pharmaceutical and healthcare industries are investing in the development of new therapies.
Yet the report's authors heavily criticize the way that some players are profiting from patients' often desperate medical situations.
Are patients being exploited?
In August, FDA commissioner Dr. Scott Gottlieb issued a statement saying that "[...] dishonest actors exploit the sincere reports of the significant clinical potential of properly developed products as a way of deceiving patients and preying on the optimism of patients facing bad illnesses."
As part of the crackdown "to prevent unscrupulous actors from being able to deceive patients and potentially harm their health," the FDA issued a warning to a stem cell clinic in Florida for "marketing stem cell products without FDA approval."
In this particular case, stem cells from fat were isolated and given to patients intravenously or injected directly into the spinal cord for a variety of conditions, despite a complete absence of scientific or medical evidence to support this type of treatment.
The clinic was also found to have failed to adhere to guidelines that intend to prevent microbial contamination when processing the stem cells, leaving patients at risk of being treated with contaminated cells.
"So the question remains about what to do about desperate patients paying huge sums of money for unproven treatments," the commissioners write.
Strict regulation and crackdowns by health authorities on institutions that offer unlicensed products are going to be key to keeping patients safe.
What does the future hold?
Scientific advances in stem cell and regenerative medicine research are hailed as breakthroughs. But a study breakthrough does not mean a new therapy, which often leads to a conflict between public expectation and the speed at which new treatments can be developed.
However, regenerative medicine does have a track record of success - albeit in a very small number of diseases.
"More complex diseases such as diabetes or heart infarct will require more advanced approaches than what [is] available today in order to see a significant clinical impact. Overall, I doubt that regenerative medicine will have an impact on global health such as vaccines had, at least in the immediate future."
Prof. Giulio Cossu
However, Prof. Cossu did highlight to MNT the huge potential that regenerative medicine has. He said, "[F]rom the first blood transfusion to bone marrow transplantation, cloning, development of viral vectors, ES [embryonic stem cells] and, more recently, iPS [induced pluripotent stem] cells, genome editing and organoids hold great promise for the future."
So, the concept remains the same: take cells from a donor, biomaterials, or molecules - or any combination thereof - and put them into a patient to treat their disease or injury.
To move regenerative medicine into the realms of mainstream medicine, better science and better regulation must be integrated with both innovative manufacturing methods that make treatments affordable, and a way to show how they ultimately benefit the patient and society as a whole.
The commissioners conclude that "[e]xploration is essential for companies and academics to move the field forward, balancing risks, costs, and potential benefits as much as possible."
"How we proceed in this new global terrain might be the biggest challenge of all for researchers, doctors, patients, relatives, regulators, and society as a whole."