Oral laquinimod in patients with relapsing-remitting multiple sclerosis: 36-week double-blind active extension of the multi-centre, randomized, double-blind, parallel-group placebo-controlled study

Background: Laquinimod, an oral novel immunomodulator, was shown to reduce MRI-measured disease activity in relapsing-remitting MS (RRMS) patients. Objectives: To determine whether the safety and efficacy profile of laquinimod, as shown in a placebo-controlled 36-week trial (LAQ/5062), is sustained and reproducible. Methods: Two hundred and fifty seven patients entered the extension phase in which MRI was performed at the beginning and at the end of the active extension phase. Clinical assessments were performed at weeks 4, 12 and every 12 weeks thereafter. Results: Two hundred and thirty nine (93%) patients completed the extension phase and 222 (86.3%) had a final scan available. Gadolinium-enhanced (GdE) T1 lesions were significantly reduced for patients switching from placebo to 0.3/0.6 mg doses (52%, p = 0.0006). In patients initially randomized to 0.6 mg in LAQ/5062 the reduction of MRI activity observed in the placebo-controlled phase was maintained in the extension. The proportion of GdE-free patients for those who switched from placebo increased from a baseline of 31% to 47% at the end of the extension phase (p = 0.01). The most prominent safety signal was elevations of liver enzymes, reversible in all cases. Conclusions: The good efficacy and the excellent safety and tolerability profiles of laquinimod 0.6 mg/day are confirmed in this extension study.