Treatment with laquinimod reduces development of active MRI lesions in relapsing MS

Background: Laquinimod is a novel immunomodulatory substance developed as an orally available disease modifying treatment in multiple sclerosis ( MS). The purpose of this study was to evaluate safety, tolerability, and efficacy on MRI lesions of two different doses of laquinimod compared with placebo in patients with relapsing MS. Methods: In this multicenter, double-blind, randomized trial, patients with relapsing MS received 0.1 mg or 0.3 mg laquinimod or placebo as three daily tablets for 24 weeks. Gadolinium- enhanced brain MRI scans were performed at screening, every eighth week during treatment, and 8 weeks after end of treatment. The primary efficacy variable was the cumulative number of active lesions over 24 weeks. Safety measures included adverse events, physical examination, and laboratory variables. Results: Of 256 screened patients, 209 were randomized (67 to 74 patients per group) in 20 centers. There was a significant difference between laquinimod 0.3 mg and placebo for the primary outcome measure ( mean cumulative number of active lesions reduced by 44%). In the subgroup of patients with at least one active lesion at baseline the reduction was slightly more pronounced (52%). No differences with respect to clinical variables (relapses, disability) were found. The safety profile was favorable; there were no clinical signs of undesired inflammatory manifestations. Conclusion: Oral laquinimod in a dosage of 0.3 mg daily was well tolerated and effective in suppressing development of active lesions in relapsing multiple sclerosis.