 This study, an extension to Study 205MS201 NCT00390221, will evaluate the long-term safety, efficacy, and immunogenicity of DAC HYP in MS. In Study 205MS201, study treatment was scheduled to stop at the Week 52 visit. This extension study will provide for the initiation of active therapy with DAC HYP among participants who received placebo during Weeks 0 through 52 in 205MS201. In addition, participants who received active therapy with DAC HYP during Weeks 0 through 52 in Study 205MS201 will continue DAC HYP therapy or resume DAC HYP therapy after a 6-month washout period in this study. 