(A) Cumulative incidence of response (recovery or improvement), overall survival according to response (B), and duration of neutropenia before hematopoietic stem cell boost (C). A response was observed in 26 patients (84%), and the median time to response after the boost was 9 days (95% CI, 7-14) in all patients. All nonresponders died within the first year after HSCB, showing 1-year OS of 0% vs a 1-year OS of 74% (95% CI, 54-94; P < .001) for responders. The 1-year OS for neutropenia ≤38 days was 85% (95% CI, 65-100) vs 44% (95% CI, 27-61; P = .029) for neutropenia >38 days before HSCB.