Survival by MRD status. (A) Median PFS not reached in both groups; relapses among MRD-positive patients were 23/91; relapses among MRD-negative patients were 1/70 (P < .001). (B) Median OS not reached in both groups; deaths among MRD-positive patients were 11/91; there were no deaths among the 70 MRD-negative patients (P = .006). (C) PFS according to MRD status and IWCLL/NCI-WG. Relapses among MRD-positive patients in CR were 3/37; relapses among MRD-negative patients in CR were 1/62 (P = .23). Relapses among MRD-positive patients in PR were 20/54; there were no relapses among the 8 MRD-negative patients in PR (P = .03). (D) OS according to MRD status and IWCLL/NCI-WG response. Deaths among MRD-positive patients in CR were 1/37; there were no deaths among the 62 MRD-negative patients in CR (P = .27). Deaths among MRD-positive patients in PR were 10/54; there were no deaths among the 8 MRD-negative patients in PR (P = .17).