WBC < 10 x 109/ l, platelet < 450 x 109/ l, myelocyte+metamyelocyte < 5% in blood, no blasts and promyelocytes in blood, basophils < 20%, no extramedullary involvement Cytogenetic response criteria: complete (0% Ph+ metaphases), partial (1– 35%), minor (36– 65%) or minimal (66– 95%).