A Novel Immunosuppression Intervention for the Treatment of Amyotrophic Lateral Sclerosis (ALS)

In an ongoing safety trial of neural stem cell injections into the spinal cord of patients with ALS at Emory University, Atlanta, Georgia, one patient has demonstrated clear improvement by objective clinical and electrophysiological measures, a finding that is unheard of in patients with ALS.

This patient had an improvement in ALSFRS-R by 1.4 points per month. In 826 historical controls from the Northeast ALS Consortium (NEALS) and the Western ALS Consortium (WALS) database where ALSFRS-R was documented at 2 or more visits, there have been no patients that have shown improvement in ALSFRS as seen in this case. Additionally, 5 patients in the stem cell trial who were not on mechanical ventilators at the time of surgery seem to have very slow disease progression as compared to the expectation from current understanding of typical disease course. This observation raises consideration for a disease-modifying effect of the novel immunosuppression regimen used in this trial. Also, given that ALS is clinically an extraordinarily heterogeneous disease, the diagnosis of ALS may represent a group of phenotypically similar but pathogenically variable disorders. It is possible that there exists a subset of patients with an immune-responsive ALS subtype that has not been previously recognized.

Recent studies have furthered the understanding of the immune mechanisms that contribute to ALS progression. Microglia and lymphocytes have both neurotoxic and neuroprotective functions depending on activation states and physiologic conditions within the nervous system. Therefore, targeted immunotherapies that proportionally suppress neurotoxic immune elements, while sparing or promoting protective elements, seemingly have more potential to modify disease course in ALS than previously tested regimens. It is postulated that the immunosuppression treatment given to the stem cell patients may have exhibited neuroprotective effects by favorably promoting the ratio of regulatory T cells and other protective immune mediators in relation to neurotoxic immune modulators. It is hoped that this trial will optimize the chance of replicating these findings and advance knowledge about the complex changes that occur within the immune system in patients with ALS before and after treatment with an immunosuppression regimen.

The primary outcome measure will be rate of change of ALSFRS-R. A clinical response will be defined as a rate of change of ALSFRS-R of +6 points over a 6 month period (mean of change of +1 point per month).

Secondary outcome measures will include slow vital capacity (SVC), grip strength, and hand held dynamometry (HHD). The change in rate of progression in clinical measures will be monitored to look for a potential disease-modifying effect of the immunosuppression regimen. Blood and cerebrospinal fluid immune system markers will be also be studied.