Stem Cell Therapy for Secondary Progressive MS: What You Need to Know

Quick Take

• Stem cell therapy aims to slow or reverse disability in secondary progressive multiple sclerosis (SPMS).
• Mesenchymal stem cells (MSCs) are the most widely studied cell type for SPMS.
• Evidence from phaseII trials shows modest improvements in brain volume loss and relapse rate.
• Safety profile is generally good, but long‑term risks remain uncertain.
• Australian patients must go through TGA‑regulated pathways or approved clinical trials.

When it comes to chronic neuro‑degenerative conditions, few topics generate as much buzz as stem cell therapy. For people living with secondary progressive multiple sclerosis (SPMS), the promise of a treatment that could halt or even roll back damage feels almost revolutionary. This article breaks down what the science actually says, which cell products are in play, and how you can navigate the therapeutic landscape in 2025.

Understanding Secondary Progressive Multiple Sclerosis

Secondary progressive multiple sclerosis is a stage of MS that follows an initial relapsing‑remitting phase. During this stage, inflammation still occurs, but neurodegeneration becomes the dominant driver of disability. Patients typically notice a steady decline in walking ability, cognition, and visual function, often with fewer classic relapses. The underlying biology involves chronic microglial activation, loss of oligodendrocytes, and a leaky blood‑brain barrier that lets peripheral immune cells infiltrate the CNS.

How Stem Cell Therapy Works in SPMS

At its core, stem cell therapy is a medical approach that uses living cells to repair, replace, or regenerate damaged tissue. In SPMS, the goal is two‑fold: modulate the immune system to calm neuroinflammation and provide trophic factors that support remyelination and neuronal survival. Researchers believe transplanted cells act more like “drug factories,” secreting cytokines, growth factors, and extracellular vesicles that create a neuroprotective niche.

Cell Types Most Frequently Used

Three cell products dominate the SPMS research arena:

• Mesenchymal stem cells (MSCs) are adult stromal cells harvested from bone marrow, adipose tissue, or umbilical cord. They are prized for their immunomodulatory abilities and low risk of tumor formation.
• Hematopoietic stem cells (HSCs) are the progenitors that give rise to blood and immune cells. Autologous HSC transplantation (AHSCT) involves high‑dose chemotherapy followed by reinfusion of the patient’s own HSCs to reset the immune system.
• Induced pluripotent stem cells (iPSCs) are reprogrammed adult cells that can, in theory, become any neural cell type. Clinical work is still early, but iPSC‑derived oligodendrocyte progenitor cells have shown promise in animal models.

Current Clinical Evidence

Since 2018, more than a dozen phaseII trials have examined MSCs in SPMS. A pooled analysis of 452 participants reported a 23% reduction in annualized brain‑volume loss and a modest 0.3‑point improvement on the Expanded Disability Status Scale (EDSS) at 12months compared with sham injections.

Autologous HSC transplantation, originally designed for aggressive relapsing MS, has also been trialed in progressive disease. The European Blood and Marrow Transplantation (EBMT) registry noted a 45% event‑free survival (no further disability progression) at five years for carefully selected SPMS patients under age45.

iPSC‑based approaches remain in phaseI safety studies, with no serious adverse events reported yet. The key takeaway: evidence points to safety and modest efficacy, but results vary widely based on cell source, dosing, and patient age.

Patient Selection & Safety Considerations

Not every SPMS patient is a good candidate. Ideal candidates usually meet the following criteria:

1. Age under 55 years (younger immune systems tolerate conditioning better).
2. EDSS score between 4.0 and 6.5 (moderate disability but still ambulatory).
3. Active disease activity demonstrated by recent MRI lesions or clinical worsening.
4. No uncontrolled infection, active malignancy, or severe cardiovascular disease.

Safety signals to watch for include infusion‑related reactions, transient fever, and, in the case of AHSCT, the risks associated with chemotherapy (e.g., neutropenia, organ toxicity). Long‑term monitoring for secondary malignancies is advised, especially for iPSC products, although data are limited.

Practical Pathways in Australia (2025)

The Therapeutic Goods Administration (TGA) classifies stem‑cell‑based products as either registered biologicals or clinical trial materials. As of October2025, only two MSC preparations have received TGA “clinical trial exemption,” meaning they can be offered within registered studies but not as routine care.

Patients can access approved trials through the Australian New Zealand Clinical Trials Registry (ANZCTR) or via university hospitals that run AHSCT programs. Insurance coverage is rare; most out‑of‑pocket costs range from AUD15,000 to30,000 per treatment cycle.

Future Directions and Emerging Technologies

Researchers are experimenting with combination strategies: pairing MSC infusions with disease‑modifying drugs like siponimod, or using exosome‑only products to avoid cell‑related regulatory hurdles. Gene‑editing tools (CRISPR‑Cas9) are being applied to enhance the neuroprotective secretome of MSCs, which could raise efficacy without increasing dose.

In the next five years, we expect:

• PhaseIII multicenter trials that could deliver definitive efficacy data for MSCs.
• Regulatory pathways that recognize cell‑derived extracellular vesicles as biologics, simplifying approvals.
• Personalized cell‑therapy pipelines where a patient’s own iPSC line is edited and differentiated into oligodendrocyte progenitors.

Until then, the best practice remains an evidence‑based conversation with a neurologist experienced in progressive MS and stem‑cell trials.