 - Must have experienced at least 1 of the following 3 conditions: a at least 1 relapse within the last 12 months prior to Day 1 with a prior brain MRI demonstrating lesions consistent with MS; b at least 2 relapses within the last 24 months prior to Day 1, with a prior brain MRI demonstrating lesions consistent with MS; c evidence of Gd-enhancing lesions of the brain on an MRI performed within the 6 weeks prior to Day 1. 