Summary Background In a phase 2 study, dexpramipexole (25–150 mg twice daily) was well tolerated for up to 9 months and showed a significant benefit at the high dose in a combined assessment of ...function and mortality in patients with amyotrophic lateral sclerosis. We aimed to assess efficacy and safety of dexpramipexole in a phase 3 trial of patients with familial or sporadic disease. Methods In our randomised, double-blind, placebo-controlled phase 3 trial (EMPOWER), we enrolled participants aged 18–80 years (with first amyotrophic lateral sclerosis symptom onset 24 months or less before baseline) at 81 academic medical centres in 11 countries. We randomly allocated eligible participants (1:1) with a centralised voice–interactive online system to twice-daily dexpramipexole 150 mg or matched placebo for 12–18 months, stratified by trial site, area of disease onset (bulbar vs other areas), and previous use of riluzole. The primary endpoint was the combined assessment of function and survival (CAFS) score, based on changes in amyotrophic lateral sclerosis functional rating scale–revised (ALSFRS-R) total scores and time to death up to 12 months. We assessed the primary endpoint in all participants who received at least one dose and had at least one post-dose ALSFRS-R measurement or died. We monitored adverse events in all participants. This study is registered with ClinicalTrials.gov , number NCT01281189. Findings Between March 28, 2011, and Sept 30, 2011, we enrolled 943 participants (474 randomly allocated dexpramipexole, 468 randomly allocated placebo, and one withdrew). Least-square mean CAFS scores at 12 months did not differ between participants in the dexpramipexole group (score 441·76, 95% CI 415·43–468·08) and those in the placebo group (438·84, 412·81–464·88; p=0·86). At 12 months, we noted no differences in mean change from baseline in ALSFRS-R total score (–13·34 in the dexpramipexole group vs −13·42 in the placebo group; p=0·90) or time to death (74 16% vs 79 17%; hazard ratio 1·03 0·75–1·43; p=0·84). 37 (8%) participants in the dexpramipexole group developed neutropenia compared with eight (2%) participants in the placebo group, and incidence of other adverse events was similar between groups. Interpretation Dexpramipexole was generally well tolerated but did not differ from placebo on any prespecified efficacy endpoint measurement. Our trial can inform the design of future clinical research strategies in amyotrophic lateral sclerosis. Funding Biogen Idec.
Summary Background Neurite outgrowth inhibitor A (Nogo-A) is thought to have a role in the pathophysiology of amyotrophic lateral sclerosis (ALS). A monoclonal antibody against Nogo-A showed a ...positive effect in the SOD1G93A mouse model of ALS, and a humanised form of this antibody (ozanezumab) was well tolerated in a first-in-human trial. Therefore, we aimed to assess the safety and efficacy of ozanezumab in patients with ALS. Methods This randomised, double-blind, placebo-controlled, phase 2 trial was done in 34 centres in 11 countries. Patients aged 18–80 years with a diagnosis of familial or sporadic ALS were randomly assigned (1:1), centrally according to a computer-generated allocation schedule, to receive ozanezumab (15 mg/kg) or placebo as intravenous infusions over 1 h every 2 weeks for 46 weeks, followed by assessments at week 48 and week 60. Patients and study personnel were masked to treatment assignment. The primary outcome was a joint-rank analysis of function (ALS Functional Rating Scale-Revised) and overall survival, analysed at 48 weeks in all patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov , number NCT01753076 , and with GSK-ClinicalStudyRegister.com , NOG112264, and is completed. Findings Between Dec 20, 2012, and Nov 1, 2013, we recruited 307 patients, of whom 303 were randomly assigned to receive placebo (n=151) or ozanezumab (n=152). The adjusted mean of the joint-rank score was −14·9 (SE 13·5) for the ozanezumab group and 15·0 (13·6) for the placebo group, with a least squares mean difference of −30·0 (95% CI −67·9 to 7·9; p=0·12). Overall, reported adverse events, serious adverse events, and adverse events leading to permanent discontinuation of study drug or withdrawal from study were similar between the treatment groups, except for dyspepsia (ten 7% in the ozanezumab group vs four 3% in the placebo group), depression (11 7% vs five 3%), and diarrhoea (25 16% vs 12 8%). Respiratory failure was the most common serious adverse event (12 8% vs seven 5%). At week 60, the number of deaths was higher in the ozanezumab group (20 13%) than in the placebo group (16 11%), mainly as a result of respiratory failure (ten 7% vs five 3%). Two deaths were considered related to the study drug (bladder transitional cell carcinoma in the ozanezumab group and cerebrovascular accident in the placebo group). Interpretation Ozanezumab did not show efficacy compared with placebo in patients with ALS. Therefore, Nogo-A does not seem to be an effective therapeutic target in ALS. Funding GlaxoSmithKline.