Multiple sclerosis (MS) is a debilitating, progressive neurological disease characterized by inflammation of the central nervous system (CNS), resulting in demyelination and axonal damage (for review see [Compston, 2008]). The clinical course for ~85% of MS patients at diagnosis is a relapsing remitting (RRMS) form, characterized by recurrent episodes of neurological dysfunction (relapses) interspersed with longer periods of gradual improvement (remissions). Typical symptoms during RRMS include limb weakness, sensory disturbance and visual impairment. Over time, disability accumulates such that after 10 years approximately half of RRMS patients do not suffer further relapses but show gradual progression of disability, termed secondary progressive (SP) MS [Confavreuax, 2000]. Excess mortality due to MS and quality of life is improving through more rapid and accurate diagnosis combined with better complication management and administration of disease modifying therapies [Bronnum, 2006]. However, more efficacious and better tolerated medicines are needed to relieve the considerable social and economic burden associated with MS.