Summary: An international team has completed a first-in-human study evaluating neural stem cell injections into the brains of people with progressive multiple sclerosis (MS). The early-stage trial found the procedure to be safe and well tolerated over 12 months and produced signals consistent with a neuroprotective effect that may help stabilise disease progression.
This experimental approach—direct transplantation of neural stem cells—represents a promising step toward advanced cell therapies for secondary progressive MS, a phase of disease for which effective treatments are limited.
Key Facts:
- Fifteen people with secondary progressive MS received neural stem cell injections directly into the brain and were followed for 12 months without any treatment-related deaths or serious adverse events.
- Over the study period, participants showed clinical stability with no clear disease progression; biomarker analyses suggested a dose-related neuroprotective signal linked to changes in brain metabolism and fatty acid profiles.
- The multicentre trial, led by teams at the University of Cambridge, University of Milano-Bicocca and Italian and Swiss hospitals, advances the development of cell therapy as a potential treatment option for progressive MS.
Study overview
Researchers from the University of Cambridge, University of Milano-Bicocca and collaborating hospitals in Italy, Switzerland and the United States conducted an early-phase clinical trial to assess safety, tolerability and preliminary biological effects of neural stem cell transplantation in people with secondary progressive MS. The study injects neural stem cells directly into the central nervous system, aiming to reduce inflammation and protect nerve cells from further damage.
Worldwide, more than two million people live with MS. Although immunomodulatory treatments can reduce relapses for many, a substantial proportion of people progress to a secondary progressive phase over decades, during which disability steadily increases. In progressive MS, chronic inflammation and immune-mediated damage to myelin and nerve cells—driven in part by microglia and other macrophage-type cells in the central nervous system—contribute to accumulating disability.
Stem cell therapies aim to modify this inflammatory environment and promote repair. Preclinical studies from the Cambridge group showed that skin cells reprogrammed into neural stem cells and transplanted into the central nervous system reduced inflammation and supported tissue repair in animal models. Building on that work, this trial tested a similar concept in people.
Fifteen participants with advanced secondary progressive MS—many requiring wheelchairs at baseline—received intracerebral injections of neural stem cells derived from donated fetal brain tissue from a single donor. The research team has demonstrated the potential to expand cells from one donor to create a large-scale supply, and future work may explore autologous approaches that derive cells from the patient to avoid allogeneic tissue challenges.
Over 12 months of follow-up, investigators recorded no treatment-related deaths or serious adverse events. Reported side effects were transient or reversible. Clinically, none of the participants displayed clear worsening of disability, cognitive decline, or relapses during the follow-up period, suggesting substantial disease stability in this small cohort.
Beyond clinical assessments, the study examined imaging and fluid biomarkers. A subgroup analysis showed that higher stem cell doses were associated with smaller reductions in brain tissue volume over time, a finding the authors suggest could reflect reduced inflammation or tissue protection. Metabolic studies of cerebrospinal fluid and blood revealed dose-related changes linked to fatty acid processing in the brain; these metabolic markers correlated with treatment dose and persisted through the 12 months, supporting a possible mechanism by which transplanted cells influence microglial function and neuroprotection.
Lead investigator Professor Stefano Pluchino (University of Cambridge) emphasised the urgent need for new therapies for secondary progressive MS and described the findings as an encouraging step toward a cell-based treatment, while acknowledging limitations such as small sample size and potential confounding effects from perioperative immunosuppression. Co-leader Professor Angelo Vescovi (University of Milano-Bicocca) noted that nearly three decades of basic research on brain stem cells have culminated in this experimental clinical application and that larger efficacy trials are needed.
Patient and charity representatives welcomed the safety data and the suggestion that this approach might stabilise progression in some people with MS, while underscoring the need for larger, controlled trials to confirm benefit and determine long-term outcomes.
About this stem cell therapy and multiple sclerosis research news
Author: Craig Brierley
Source: University of Cambridge
Contact: Craig Brierley – University of Cambridge
Image: Image credited to Neuroscience News
Original Research: Findings reported in Cell Stem Cell