The drug rhIGF-1 (CEP-151) has been shown to play a key role preclinically in oligodendrocyte differentiation and survival, as well as, myelin integrity and function. Moreover, in an animal model of MS, myelin expression, as well as that of its receptors is upregulated at the time the myelin sheaths regenerate. Finally, administration of exogenous rhIGF-1 to rats with EAE effectively, closes the disrupted BBB, reduces the number and severity of demyelinating lesions, and improves neurological function. Thus it seems reasonable to examine the efficacy and safety, tolerability, and effect of CEP-151 on brain MRI lesions in patients with MS.