CR was defined as the presence of all of the following improvements: (1) bone marrow: ≤5% myeloblasts (including monocytic blast equivalent) and no lymphoblasts, with normal maturation of all cell lines, and return to age-adjusted normal cellularity; (2) osteomyelofibrosis absent or equal to "mild reticulin fibrosis" (Grade 1 or less fibrosis); (3) peripheral blood: white blood cells (WBC) ≤10 x 10\^9 cells/Liter (L); hemoglobin (Hgb) ≥11 grams per deciliter (g/dL); platelets ≥100 x 10\^9/L and ≤450 x 10\^9/L; neutrophils ≥1.0 x 10\^9/L; blasts = 0%; neutrophil precursors reduced to ≤2%; monocytes ≤1 x 10\^9/L; eosinophils ≤0.5 x 10\^9/L; (4) extramedullary disease: complete resolution of extramedullary disease present before therapy (e.g., lymphadenopathy), including palpable hepatosplenomegaly. Persistent low-level dysplasia was permitted given subjectivity of assignment of dysplasia. Response criteria by investigator assessment were the same for chronic phase (CP) and blast phase (BP).