A double-blind placebo-controlled clinical trial of subcutaneous recombinant human ciliary neurotrophic factor (rHCNTF) in amyotrophic lateral sclerosis. ALS CNTF Treatment Study Group

Abstract

Ciliary neurotrophic factor (CNTF) is a neuroactive cytokine found in Schwann cells, which appears to be released in response to nerve injury. The ALS CNTF Treatment Study (ACTS) clinical trial was a phase II-III randomized, placebo-controlled, double-blind study designed to evaluate the safety, tolerability, and efficacy of subcutaneous administration of recombinantly produced human CNTF (rHCNTF) in slowing disease progression in 730 patients with amyotrophic lateral sclerosis (ALS). Patients were randomized to receive 30 micrograms/kg or 15 micrograms/kg rHCNTF or placebo subcutaneously three times a week for 9 months. The primary endpoint of the study, the slope of decline of isometric muscle strength in treated versus placebo patients, showed no statistically significant difference between rHCNTF and placebo-treated patients, and was complicated by an initial statistically significant decrease in strength early in rHCNTF-treated patients. Mortality was similar in all three study arms. There were no statistically significant treatment effects among the secondary measures. Side effects of rHCNTF included anorexia, weight loss, and cough and were sufficient to limit dosing in many patients.