Adipose-derived mesenchymal stem cells for the treatment of Amyotrophic Lateral Sclerosis. A phase I/II safety and efficacy clinical trial.

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) is a progressive and fatal neurodegenerative disease with few treatments available. Mesenchymal stem cells have arisen as a potential treatment option for ALS due to their immune system modulation and their neuroprotective effects. This clinical trial aimed to evaluate the safety, efficacy and feasibility of three intravenous doses of autologous adipose-derived mesenchymal stem cells (AdMSC) in ALS patients.

METHODS

A multicentre, randomized, parallel group, placebo-controlled, double-blinded clinical trial (EudraCT: 2011-006254-85) was conducted in 40 patients with ALS in treatment with riluzole. Patients were randomized 1:1:1:1 into the following treatment groups: 1 × 10 cells/kg, 2 × 10 cells/kg, 4 × 10 cells/kg and placebo. After a 6 month follow-up, patients in the placebo group were randomized 1:1:1 to receive one of the three doses of AdMSC and they were followed up for another 6 months. Lastly, all patients were followed-up in a 36-month open-label extension. Safety was mainly assessed through the evaluation of adverse events and their relationship with the medicinal product. Several variables were measured to assess efficacy, such as ALS Functional Rating Scale, Ashworth spasticity scale, neurophysiological and neuropsychological parameters and overall survival. The feasibility of the procedure was assessed through the evaluation of the extraction and infusion of AdMSC.

RESULTS

Safety of AdMSC was observed through all follow-up periods, with similar percentages of adverse events between groups and no significant differences between groups in the rate of adverse events related to treatment. The administration procedure was feasible for all patients. Across all analyzed measures, we observed the expected progressive decline characteristic of ALS, with no statistically significant between-group differences in the rate of change.

DISCUSSION

The results obtained in this study are consistent with the ones obtained in other clinical trials using similar doses of MSC, where safety was demonstrated and efficacy results were inconclusive, due to not reaching statistical significance. Larger studies with an increased sample size, different doses and route of administration or combination of routes, repeated dosing or larger duration and comprehensive assessment of immunological effect would be needed to analyze the efficacy of AdMSC in the treatment of ALS.

CLINICAL TRIAL REGISTRATION

https://www.clinicaltrialsregister.eu/ctr-search/search?query=2011-006254-85.