Stem Cell Therapy for Multiple System Atrophy

What This Article Covers

Multiple system atrophy (MSA) is a rare, rapidly progressive neurodegenerative disease with no disease-modifying treatment and no cure — a gap that has made it one of the more actively studied conditions for mesenchymal stem cell (MSC) research. This article covers what MSA is, why researchers believe MSCs might help, and what a genuinely encouraging but still early body of clinical trial evidence — including a landmark randomized trial and several small dose-escalation studies out of South Korea and the Mayo Clinic — actually shows, alongside the real safety questions and the current, unambiguous answer on FDA approval.

Overview

Multiple system atrophy is a rare condition, related to Parkinson's disease, in which nerve cells in several parts of the brain and spinal cord progressively degenerate. It causes a mix of parkinsonism (slowness, stiffness), cerebellar ataxia (loss of coordination and balance), and autonomic failure (blood pressure regulation problems, bladder dysfunction). MSA typically progresses faster and responds far more poorly to standard Parkinson's medications than Parkinson's disease itself, and average survival after diagnosis is commonly cited in the range of 6 to 10 years. Because no approved therapy slows the underlying degeneration, MSA is a condition where patients and families are especially motivated to look toward experimental and regenerative approaches.

How It's Thought to Work

MSCs — most often harvested from a patient's own bone marrow or fat tissue — are not generally believed to become new neurons and physically replace what MSA destroys. Instead, the leading hypothesis is that MSCs act as a kind of biological support system: they secrete growth factors and anti-inflammatory signaling molecules that may calm neuroinflammation, support surviving neurons, and improve the local environment around damaged brain tissue. In MSA research, cells have been delivered by three main routes — injected into the spinal fluid (intrathecal), infused into the bloodstream (intravenous), or delivered directly into the brain's blood supply via a catheter (intra-arterial) — each with different theoretical advantages and different risk profiles.

What the Evidence Shows

The single most important study in this field is a randomized, double-blind, placebo-controlled trial by Lee and colleagues, published in Annals of Neurology (2012), which delivered autologous MSCs by intra-arterial infusion to patients with MSA. The treated group showed a smaller increase in disability scores on the Unified MSA Rating Scale (UMSARS) than the placebo group over the follow-up period — a genuinely notable signal, since UMSARS scores in MSA typically climb relentlessly. It remains one of only two randomized controlled trials in this space, and it helped establish that intra-arterial MSC delivery was feasible and reasonably tolerated.

Building on that work, Chung and colleagues published a Phase I dose-escalation trial in Stem Cells International (2021), testing low-, medium-, and high-dose intra-arterial MSC infusions in nine patients with the cerebellar subtype of MSA. The medium- and high-dose groups showed a trend toward a slower rate of UMSARS decline compared with the low-dose group — encouraging, though the study was far too small (and not placebo-controlled) to call this proof of benefit. Safety was reassuring: no participant showed acute stroke-type lesions on brain imaging, and while one low-dose patient had a reversible finding on MRI, the trial's authors described the overall approach as safe and worth pursuing further.

A 2025 systematic review in Biologics: Targets and Therapy pooled data across seven MSA cell-therapy studies (roughly 123 patients total, spanning intrathecal, intravenous, and intra-arterial routes) and found a consistent pattern: adverse events were generally mild and largely tied to the delivery procedure itself rather than to the cells, with no clear signal of serious MSC-related toxicity across studies — a meaningfully reassuring safety picture for a fatal disease with few other options. Efficacy signals varied by study and were strongest in smaller, non-randomized trials, including one report of MSA patients receiving intrathecal adipose-derived MSCs progressing markedly slower than historical controls. The review's authors were careful to note, however, that small samples, inconsistent protocols, and short follow-up mean these results cannot yet be treated as confirmed disease-modifying benefit.

The field is now moving toward more definitive answers: the Mayo Clinic is running a randomized, double-blind, placebo-controlled Phase II trial (ClinicalTrials.gov identifier NCT05167721) of repeated intrathecal autologous adipose-derived MSC injections in roughly 70 to 76 participants with MSA, using change in total UMSARS score over 12 months as its primary outcome. This is the kind of larger, rigorously controlled trial the field has been waiting for, and its results — expected after the study's primary completion — should meaningfully sharpen what we actually know.

Who Might Be a Candidate

• Adults with a clinical diagnosis of probable or possible MSA (parkinsonian or cerebellar subtype)
• Patients in relatively early-to-moderate disease stages, where trials have generally seen the clearest potential to slow, rather than reverse, decline
• Individuals who have exhausted or poorly tolerated standard symptomatic treatments (such as levodopa)
• People without contraindications to the specific delivery procedure being studied (e.g., bleeding risk for intra-arterial approaches, prior spinal issues for intrathecal delivery)
• Patients able and willing to participate in a formal, IRB-approved clinical trial with structured monitoring — not an unregulated clinic offering “stem cell treatment” outside of research

Given how early-stage and procedure-dependent this evidence is, MSA is a condition where trial enrollment, not commercial treatment, is the responsible path for now.

Bottom Line

MSA is exactly the kind of relentless, currently untreatable disease where the cautious optimism around MSC research feels earned: a randomized trial has shown a real signal of slowed decline, dose-escalation work has reinforced that the intra-arterial and intrathecal approaches appear reasonably safe, and a large, well-designed Mayo Clinic trial is now underway to test the question properly. That said, no stem cell therapy is FDA-approved for MSA, the positive findings so far come from small studies, and this remains investigational medicine — best pursued, for now, only through registered clinical trials rather than direct-to-consumer clinics, which the FDA has repeatedly warned can expose patients to real physical harm without proven benefit.