 The choice of placebo as treatment control is essential to obtain information on the specific compared to non-specific effects of active treatment and provides the best way of evaluating the efficacy and of assessing the true safety and tolerability profile of BAF312. Short-term placebo exposure 6 Period 1 or 3 Period 2 months, respectively is unlikely to lead to longer term differences in outcomes Polman, 2008. The use of an adaptive design strategy contributes to a significant reduction of placebo exposure, both in terms of the number of patients and duration, as compared to conventional trial models. 