Evaluate Early Glatiramer Acetate Treatment in Delaying Conversion to Clinically Definite Multiple Sclerosis of Subjects Presenting With Clinically Isolated Syndrome

The primary objective is to assess the effect of treatment with glatiramer acetate (GA) compared to placebo on the time to conversion to CDMS, as determined by Poser criteria (the occurrence of the second clinical attack) during the double-blind period. The secondary objective is to assess, within the time frame of the up to 3-year double-blind, placebo-controlled study period, the effect of GA on clinical and Magnetic Resonance Imaging (MRI) parameters. The long-term objectives of the study (exploratory in nature) are to assess, within the time frame of 5 years, the neuroprotective effect of early versus delayed treatment with GA as reflected by clinical and MRI parameters measuring the accumulated irreversible brain tissue damage. A pre-planned interim analysis was performed on all efficacy and safety data accumulated in the database up to October 14, 2007, i.e. when 81% of exposure to treatment in the double-blind, placebo-controlled period had been collected. Upon review of the interim analysis results, the Data Monitoring Committee (DMC) recommended that the double-blind portion of the study be stopped and that subjects be switched to the 2-year Open-label period, during which time they would have the option of receiving GA therapy. The sponsor (Teva) adopted the DMC recommendations and took the necessary action towards its implementation.