A new study adds important detail to the ongoing investigation of stem cell-based therapies for progressive multiple sclerosis (MS). Rather than asking only whether treatment changes symptoms or disability scores, researchers examined whether repeated injections of a patient’s own stem cell–derived neural progenitor cells produce measurable biological changes in the fluid surrounding the brain and spinal cord. The answer was yes—but the findings should be viewed as an early step toward understanding how this experimental treatment may work, not as proof that it can yet halt or reverse progressive MS.
Progressive MS remains especially difficult to treat. While disease-modifying therapies have substantially improved care for many people with relapsing-remitting MS, people with primary progressive MS (PPMS) or secondary progressive MS (SPMS) can continue to accumulate disability even when obvious inflammatory activity, such as relapses or new MRI lesions, is limited. This creates a need for treatments that may protect nervous-system tissue, influence harmful inflammation, or support repair.
A treatment built from patients’ own cells
The therapy studied was called mesenchymal stem cell–neural progenitor, or MSC-NP, treatment. Researchers first collected bone marrow from each participant and used the cells to produce a neural progenitor-like population in the laboratory. These cells are not intended simply to replace damaged nerve cells. Instead, they are thought to release signals that may alter immune activity, support nerve-cell survival, and encourage a more repair-friendly environment in the central nervous system.
The cells were delivered intrathecally—by injection into cerebrospinal fluid (CSF), the clear fluid that surrounds the brain and spinal cord. This route is designed to bring the treatment closer to the tissues affected by MS.
The study analyzed samples from two groups of people with non-active progressive MS. One group included 50 participants in a phase 2 clinical trial who received six injections over roughly a year. A second, independent expanded-access group included 43 participants who received three injections over a shorter period. Most participants had SPMS, while about one in five had PPMS.
Four CSF biomarkers changed consistently
The researchers looked for treatment-related changes in proteins within CSF. They identified four biomarkers that changed after MSC-NP treatment in both participant groups:
- CCL2 decreased
- Stem cell factor (SCF) decreased
- MMP9 increased
- CHIT1 increased
Importantly, these changes were found in CSF but not in blood serum. That pattern suggests the treatment may be producing a localized biological response within the central nervous system rather than a broad, body-wide effect. The researchers also found that these biomarker shifts did not occur after placebo saline injections, making it less likely that they were caused simply by repeated spinal-fluid procedures.pm
CCL2 is particularly interesting because it is a chemical signal involved in recruiting immune cells and is linked to inflammatory activity in MS lesions. Its decline after treatment may indicate reduced activity of inflammatory cells such as microglia, the immune cells that reside in the brain and spinal cord.
The increases in MMP9 and CHIT1 are harder to interpret. Both have been associated with inflammation in other MS contexts. However, the authors note that MMP9 may also help reshape the tissue environment in ways that support remyelination, while CHIT1 may be connected to microglial activity and the maturation of oligodendrocytes—the cells that make myelin. At this stage, these proposed repair-related interpretations remain hypotheses rather than demonstrated mechanisms.pmc.n
What did not change—and why that matters
Two widely studied MS biomarkers, neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP), did not show a meaningful treatment-related change. NfL is commonly used as an indicator of nerve-cell injury, while GFAP can reflect astrocyte activation and disease progression. Their stability may partly reflect the study population: participants had non-active progressive MS and generally low baseline NfL levels.pmc
The study also did not establish that biomarker changes directly translated into improved walking, disability, cognition, or long-term disease progression. That is a major limitation. Biomarkers can show that a therapy is biologically active, but they cannot on their own demonstrate a clinically meaningful benefit.
