Dose-ranging study of riluzole in amyotrophic lateral sclerosis. Amyotrophic Lateral Sclerosis/Riluzole Study Group II. A controlled trial of riluzole in amyotrophic lateral sclerosis. ALS/Riluzole Study Group. A study of riluzole in the treatment of advanced stage or elderly patients with amyotrophic lateral sclerosis.
Amyotrophic lateral sclerosis (ALS) is a progressive disease with no effective treatment. In an initial study, riluzole decreased mortality and slowed muscle-strength deterioration in ALS patients. We have carried out a double-blind, placebo-controlled, multicentre study to confirm those findings and to assess drug efficacy at different doses.
                959 patients with clinically probable or definite ALS of less than 5 years' duration were randomly assigned treatment with placebo or 50 mg, 100 mg, or 200 mg riluzole daily; randomisation was stratified by centre and site of disease onset (bulbar or limb). The primary outcome was survival without a tracheostomy. Secondary outcomes were rates of change in functional measures (muscle strength, functional status, respiratory function, patient's assessments of fasciculation, cramps, stiffness, and tiredness). The primary analysis was the comparison of the 100 mg dose with placebo by intention-to-treat. Drug-effect on survival was assessed before (log-rank test) and after adjustment for known prognostic factors (Cox's model).
                At the end of the study, after median follow-up of 18 months, 122 (50.4%) placebo-treated patients and 134 (56.8%) of those who received 100 mg/day riluzole were alive without tracheostomy (unadjusted risk 0.79, p = 0.076; adjusted risk 0.65, p = 0.002). In the groups receiving 50 mg and 200 mg riluzole daily, 131 (55.3%) and 141 (57.8%) patients were alive without tracheostomy (relative to placebo 50 mg adjusted risk 0.76, p = 0.04; 200 mg 0.61, p = 0.0004). There was a significant inverse dose response in risk of death. No functional scale discriminated between the treatment groups. The most common adverse reactions were asthenia, dizziness, gastrointestinal disorders, and rises in liver enzyme activities; they were commonest with the 200 mg dose.
                Overall, efficacy and safety results suggest that the 100 mg dose of riluzole has the best benefit-to-risk ratio. This study confirms that riluzole is well tolerated and lengthens survival of patients with ALS. Amyotrophic lateral sclerosis is a progressive motor neuron disease for which there is no adequate treatment. Some research suggests that the excitatory amino acid neurotransmitter glutamate may be involved in the pathogenesis.
                To evaluate the efficacy and safety of the antiglutamate agent riluzole, we conducted a prospective, double-blind, placebo-controlled trial in 155 outpatients with amyotrophic lateral sclerosis. The dose of riluzole was 100 mg per day. Randomization was stratified according to the site of disease onset (the bulbar region or the limbs). The primary end points were survival and rates of change in functional status. The main secondary end point was change in muscle strength. Analyses were undertaken after 12 months of treatment and at the end of the placebo-controlled period (median follow-up, 573 days).
                After 12 months, 45 of 78 patients (58 percent) in the placebo group were still alive, as compared with 57 of 77 patients (74 percent) in the riluzole group (P = 0.014). For patients with bulbar-onset disease, one-year survival rates were 35 percent (6 of 17) with placebo and 73 percent (11 of 15) with riluzole (P = 0.014), whereas for those with limb-onset disease one-year survival was 64 percent and 74 percent, respectively (P = 0.17). The survival advantage with riluzole was smaller (37 percent [29 of 78] with placebo vs. 49 percent [38 of 77] with riluzole) at the end of the placebo-controlled period, but it remained significant in the overall population (P = 0.046) as well as in the patients with bulbar-onset disease (18 percent [3 of 17] vs. 53 percent [8 of 15], P = 0.013). The deterioration of muscle strength was significantly slower in the riluzole group than in the placebo group (P = 0.028). Adverse reactions to riluzole included asthenia, spasticity, and mild elevations in aminotransferase levels. Twenty-seven patients in the riluzole group withdrew from the study, as compared with 17 in the placebo group.
                The antiglutamate agent riluzole appears to slow the progression of amyotrophic lateral sclerosis, and it may improve survival in patients with disease of bulbar onset. Treatment with the neuroprotective drug riluzole has previously been shown to increase the probability of survival in patients with amyotrophic lateral sclerosis. This report describes a placebo-controlled, double-blind randomised clinical trial of riluzole carried out in ALS patients with advanced stage disease or aged over 75 years. The primary objective was to enable access to treatment to patients excluded from the pivotal trial which was run in parallel. Another goal was to assess the safety of riluzole in patients with advanced-stage disease. One hundred and sixty-eight patients were included, randomised to either riluzole 50 mg b. i. d. or to placebo, and treated for eighteen months. Riluzole was well-tolerated in this patient population, and the adverse events observed were similar in nature and frequency to those observed in previously published clinical trials in patients included in pivotal trials. The study could not include enough patients to reach adequate power to detect differences in survival between the two treatment groups, and no such difference was in fact observed. In conclusion, riluzole is well-tolerated in ALS patients with advanced stage disease.
Riluzole 100 mg daily is reasonably safe and probably prolongs median survival by about two to three months in patients with amyotrophic lateral sclerosis.