Phase IIa trial of fingolimod for amyotrophic lateral sclerosis demonstrates acceptable acute safety and tolerability

INTRODUCTION: Immune activation has been implicated in progression of amytrophic lateral sclerosis (ALS). Oral fingolimod reduces circulating lymphocytes. The objective of this phase IIa, randomized, controlled trial was to test the short‐term safety, tolerability, and target engagement of fingolimod in ALS. METHODS: Randomization was 2:1 (fingolimod:placebo). Treatment duration was 4 weeks. Primary outcomes were safety and tolerability. Secondary outcomes included circulating lymphocytes and whole‐blood gene expression. RESULTS: Thirty participants were randomized; 28 were administered a drug (fingolimod 18, placebo 10). No serious adverse events occurred. Adverse events were similar by treatment arm, as was study discontinuation (2 fingolimod vs. 0 placebo, with no statistical difference). Forced expiratory volume in 1 second (FEV(1)) and FEV(1)/slow vital capacity changes were similar in the fingolimod and placebo arms. Circulating lymphocytes decreased significantly in the fingolimod arm (P < 0.001). Nine immune‐related genes were significantly downregulated in the fingolimod arm, including forkhead box P3 (P < 0.001) and CD40 ligand (P = 0.003). DISCUSSION: Fingolimod is safe and well‐tolerated and can reduce circulating lymphocytes in ALS patients. Muscle Nerve 56: 1077–1084, 2017