For Cohort 1, the response to treatment was determined at the end of the 12 weeks of treatment. For Cohort 2, the response to treatment was determined after 12 weeks of treatment and 24 weeks of observation. For Cohort 3, the response to treatment was determined after intermittent dosing over a 20-week period, consisting of an initial 8-week treatment period, followed by a 4-week drug holiday period, followed by a second 8-week treatment period.