Safety and Efficacy Extension Study of Daclizumab HYP to Treat Relapsing-Remitting Multiple Sclerosis

• To assess the safety and immunogenicity of extended treatment with DAC HYP (adverse events, laboratory evaluations, vital signs, physical examinations, and immunogenicity as defined by the incidence of development of antibodies to DAC HYP). [ Time Frame: 52 weeks ] [ Designated as safety issue: Yes ]
  

• The durability of DAC HYP measured by brain MRI (new Gd-enhancing lesions; new or newly-enlarging T2 hyperintense lesions; vol of new T1 hypointense lesions; total lesion vol of T2 hyperintense lesions; vol of non-Gd-enhancing T1 hypointense lesions [ Time Frame: 52 weeks ] [ Designated as safety issue: No ]
  
• The durability of the effect of DAC HYP on MS disease activity as measured by clinical MS relapses (the number of relapses based on the annualized relapse rate; and the proportion of subjects who are relapse free). [ Time Frame: 52 weeks ] [ Designated as safety issue: No ]
  

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