FDA Approval
The FDA approval of Plegridy was based on a randomized, double-blind, and placebo controlled, one-year study. The trial compared clinical and MRI outcomes at 48 weeks in patients who received Plegridy 125 micrograms (n=512) or placebo (n=500) subcutaneously once every 14 days. All subjects had a baseline Expanded Disability Status Scale (EDSS) score from 0 to 5, had experienced at least 2 relapses within the previous three years, and had experienced at least 1 relapse in the previous year. None of the subjects had progressive MS. Neurological evaluations were scheduled at baseline, every 12 weeks, and at the time of a suspected relapse. Brain MRI evaluations were scheduled at baseline, week 24, and week 48. The primary outcome was the annualized relapse rate over 1 year. The annualized relapse rate was 0.26 in the Plegridy arm and 0.40 in the placebo arm; relative reduction 36%