Response summary and timelines. Twenty of 40 patients on study 2 met primary response criteria at the defined end point of 24 weeks on EPAG (solid green bars after 24-week response assessment). Note that 5 patients achieved response only after the 12-week interim assessment (UPN3, UPN4, UPN8, UPN12, and UPN18; gray bars between first and second response assessments). UPN7 achieved response criteria at 12 weeks but not at the primary end point of 24 weeks. UPN14 reached response criteria at 12 weeks but was taken off study at that time point due to clonal evolution, and thus was a nonresponder at the primary end point of 24 weeks. Nineteen responders continued EPAG on the extension arm of the protocol. EPAG administration was stopped in 14 patients for robust response and one when blood cell counts appeared to reach a plateau (UPN16), with continuing response off EPAG designated by the green striped bars. The drug was restarted in 5 patients for declining blood cell counts off EPAG, and all responded a second time (UPN8, UPN9, UPN16, UPN37, and UPN38; solid yellow bars). *Off study for patient choice. **Off study for cytogenetic evolution.