Ongoing uncertainty and unsubstantiated claims around the use of stem cell treatments for knee osteoarthritis are highlighted in the article below, by Shauna Hurley for Cochrane Australia.
Shauna Hurley writes:
Stem cell treatments are a source of medical hope and media hype but a new Cochrane review published this month finds evidence of their promised benefits remains elusive.
The new global research report weighs up the latest evidence on stem cell injections for knee osteoarthritis – a debilitating condition that affects over two million Australians and costs the health system more than $4 billion each year.
Key findings highlight just how much uncertainty remains about the potential benefits and harms of increasingly popular but unproven treatment options that are not covered by Medicare and often come with sky high out-of-pocket costs.
Dr Sam Whittle, a Senior Consultant Rheumatologist from Adelaide’s Queen Elizabeth Hospital and Monash University, led the global Cochrane research team conducting the latest evidence analysis.
“We know knee osteoarthritis is the most common joint disease here in Australia and around the world,” he says.
“And unfortunately, it’s also a very complex condition to treat because it impacts the whole knee joint – including the bone, cartilage, ligaments and muscles. Patients experience pain and swelling that can impair movement and daily activities, reducing their quality of life over time.
“Stem cells are a special type of cell that can develop into mature cells in different parts of the body, including cells that produce cartilage, bone and fat tissue. In theory, they could rebuild cartilage, improve joint structure and reverse the damage caused by osteoarthritis.
“If anyone could demonstrate stem cells can actually do this in practice, that would be groundbreaking. To date though, we’ve seen very mixed results.”
Regulatory matters
With no available cure for knee osteoarthritis and limited effective non-surgical treatments for long-term symptom management, a range of experimental rather than evidence-based procedures continues to proliferate worldwide, usually with regulatory and consumer protections failing to keep pace.
Several private clinics offer stem cell injections here in Australia, with costs of treatment varying. Professor David Hunter, lead investigator on the ScUlpTor stem cell study currently underway in Sydney, suggests an injection of stem cells into the knee costs a minimum of $5,000 for one injection and up to $12,000 for three or four injections.
The regulatory landscape for these kinds of stem cell treatments is less than straightforward and involves a number of different agencies.
Stem cells are primarily overseen by the Therapeutic Goods Administration (TGA) through its Biologicals Regulatory Framework, because the TGA classifies stem cells as ‘biologicals’ rather than conventional drugs.
Additional oversight comes from the Medical Board of Australia (regulating practitioners), the Australian Health Practitioner Regulation Agency (handling complaints), and the Australian Competition and Consumer Commission (monitoring misleading claims).
Stem cells are currently regulated and approved by the TGA for treating blood disorders, autoimmune diseases, and cancers. However, they are not specifically regulated for use in other conditions such as osteoarthritis.
Stem cells can still be used for non-approved conditions if they are provided in a hospital setting by a medical practitioner treating their own patient.
Additionally, treatments using a patient’s own cells are exempt from the standard TGA regulations if the cells are collected and used in a same-day single procedure. The stem cells must not be combined with other materials, and be minimally processed and used for their biological purpose (such as repair or regeneration of tissue).
Notably, the TGA doesn’t allow advertising of any unapproved stem cell therapies to the public, meaning clinics can’t legally promote these treatments.
Clinics navigate this regulatory landscape in several ways. Some use the same-day procedure exemption, while others adopt different terminology like ‘regenerative medicine’ or ‘biological treatments’ rather than explicitly using the term ‘stem cell treatments’.
And rather than advertising, some clinics present would-be patients with anecdotal treatment success stories, patient testimonials, or cherry-picked single studies showing benefits during consultations. This selective approach often fails to provide people with the complete evidence picture, including the uncertainties regarding both benefits and potential harms.
“While our review is on evidence rather than regulation, we know this rapidly shifting landscape can be difficult terrain for everyone – from patients to clinicians to regulators,” Whittle says.
“When you’ve got a common chronic, painful condition that interferes with people’s quality of life, for which we have relatively few effective therapies, people become desperate and want to leave no stone unturned. Often treatments marketed as ‘natural’ because they use cells from your own body are easily sold as offering hope.
“But whatever the condition or the treatment, the take home message is that it’s essential to ask your practitioner about evidence for benefits versus harms – and not be convinced by a single positive trial or patient testimonial.
“This is why Cochrane reviews are valuable – they aggregate all available global evidence, helping people make informed decisions before investing in treatments.”
State of evidence
This latest Cochrane review addresses a specific question: do stem cell injections slow the progression of knee osteoarthritis and lead to improvements in pain, function and quality of life, or do they cause harm?
In search of an answer, Cochrane researchers looked at 25 studies involving 1,341 participants globally, including eight studies with 459 participants that directly compared stem cell injections to placebo injections.
They found:
- Stem cell injections may provide small improvements in pain and function compared with placebo injections, but showed no significant impact on quality of life or overall treatment success. The clinical significance of these modest improvements remains unclear.
- The benefits and risks of stem cell injections compared with no treatment, routine care, or glucocorticoid injections remain uncertain.
- Despite claims about regenerative effects, there is insufficient evidence regarding stem cell injections’ impact on structural progression in the knee joint.
- Safety data remains limited, with serious adverse events being infrequently reported. While all joint injections carry some risk of complications like septic arthritis, the potential long-term concerns related to therapies that promote cell growth remain unknown.
- It’s still unclear which methods of stem cell harvest, isolation, expansion, storage, injection technique, or dosage might be most effective, if any.
“Overall we found no evidence of an important benefit, though there was a small improvement in pain and function in those who received stem cells compared with placebo injections. Put simply, if there’s a benefit, it’s probably quite minor, but we can’t be very certain about this until more trial results come in,” Whittle concludes.
Making evidence-informed decisions
As global case numbers climb, the ongoing uncertainty and unsubstantiated claims around stem cell treatments for knee osteoarthritis are frustrating for everyone seeking effective treatments, and ultimately a cure.
The good news is that several major clinical trials are underway – including a large trial run out of Sydney that will effectively double the size of Cochrane’s latest meta-analysis – that set the stage for a better understanding of stem cell treatments.
“Our living review team will be screening for new evidence every three months from here on in, and as we accrue those important, large, well-conducted trials, we should get much higher confidence in our estimate of effect, and ideally some more concrete conclusions as results come in over the next two to five years,” Whittle says.
“In the meantime, current guidance includes non-drug treatments such as physiotherapy and regular exercise, maintaining a healthy weight, and cognitive behavioural therapy. Anti-inflammatory and pain medications can also play a supporting role.
“The key takeaway for anyone considering stem cell injections is to be guided by the latest evidence, which at this point in time underscores the uncertainty about both their benefits and their harms. For our part, we look forward to continuing our research and contributing to a much clearer picture to help patients, policy makers and health care providers alike in the years ahead.”
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