Overall survival and progression-free survival of lenalidomide-treated patients. (A) Overall survival for the 15-mg twice-daily and 30-mg once-daily dose groups. (B) Overall survival combined for both doses with 95% confidence interval. (C) Progression-free survival to lenalidomide (without censoring for addition of dexamethasone) for the 15-mg twice-daily and 30-mg once-daily dose groups. (D) Progression-free survival to lenalidomide (without censoring for addition of dexamethasone) for both doses combined (with 95% confidence interval). (E) Overall progression-free survival (with censoring for addition of dexamethasone) for 15 mg twice-daily and 30 mg once-daily dose groups. (F) Overall progression-free survival (with censoring for addition of dexamethasone) for both doses combined with 95% confidence interval. Dotted lines in panels B, D, and F represent the upper and lower boundaries of the 95% CI for each Kaplan-Meier curve.