Safety and Efficacy Extension Study of Daclizumab High Yield Process (DAC HYP) in Participants With Multiple Sclerosis Who Have Completed Study 205MS201 (NCT00390221) to Treat Relapsing-Remitting Multiple Sclerosis

The primary objective of the study was to assess the safety and immunogenicity of extended treatment with DAC HYP. This evaluation included the following major components: * An assessment of safety and immunogenicity of extended treatment with DAC HYP when administered to MS subjects who had completed 52 weeks of active therapy with DAC HYP in Study 201. * An assessment of safety and immunogenicity during a 6-month washout period from DAC HYP. * An assessment of safety and immunogenicity during reinitiation of therapy with DAC HYP after a 6-month washout period. * An assessment of safety and immunogenicity of DAC HYP when administered to MS subjects who previously received placebo during Study 201. The secondary objective is to assess the durability of the effect of DAC HYP on multiple sclerosis (MS) disease activity as measured by brain magnetic resonance imaging (MRI) scans and clinical MS relapses.