PFS of patients with isolated high-risk lesions by maintenance randomization. Kaplan-Meier plots for PFS for patients with isolated/single-hit del(1p) (A), del(17p) (B), t(4;14) (C), or gain(1q) (D) for randomization groups for Len maintenance (maint) (blue) or observation (Obs) (red); P values: Wald-P.