Laquinimod is rapidly absorbed following oral administration with bioavailability of 82%-95%. Two Phase 2 clinical trials were conducted with laquinimod. Both demonstrated a reduction in the frequency of gadolinium (Gd)-enhancing lesions and relapses in patients with relapsing-remitting multiple sclerosis (RRMS) and secondary progressive multiple sclerosis (SPMS). Laquinimod was well tolerated in both Phase 2 trials with few side effects. There was no difference in the overall number of adverse events (AEs) or serious adverse events (SAEs) between the placebo and laquinimod groups. Laquinimod effectively ameliorates both acute and chronic experimental autoimmune encephalomyelitis (EAE) decreasing both demyleination and axonal loss. Laquinimod may have protective effects on axonal integrity beyond that associated with decreased inflammation. Laquinimod has no immuno suppressive effects in animal models or in human studies, and does not decrease the ability of animals to mount a cellular or humeral immune response. The safety profile of laquinimod appears quite favorable.