OS according to Len duration, IMiD-free interval, and last Len dose. (A) OS according to a Len duration <12 months (blue line) or ≥12 months (red line). (B) OS according to an IMiD-free interval <18 months (blue line) or ≥18 months (red line). (C) OS according to last Len dose (5-15 mg) (blue line) vs 25 mg (red line).