Individual subject responses to dexpramipexole. (A-C) AEC (left axis, black line) and percentage baseline GC dose (right axis, gray shading) are shown for individual subjects over the first 12 months of the study grouped by responders (A), nonresponders (B), and delayed responders (C). The dotted vertical line indicates the primary study end point. Dexpramipexole administration is indicated by the horizontal line/arrow above the graph.