Treatment of blastic transformation of chronic myelogenous leukemia with mitoxantrone

Twenty-four patients with blastic-phase chronic myelogenous leukemia (CML) were treated with mitoxantrone. The patients included 19 whose cells were Philadelphia chromosome (Ph1+) and 5 who were either Ph1- or in whom cytogenetics were not available. Six of the 19 whose cells were Ph1+ responded and one of those who were Ph1- responded. The patients were further characterized into lymphoid or nonlymphoid on the basis of terminal deoxynucleotidyl transferase or morphology. Two of the patients with lymphoid transformation and 3 of those with nonlymphoid transformation responded. In 3 patients post-treatment cytogenetic evaluation revealed the presence of Ph1- metaphases. We conclude that mitoxantrone has modest activity in blCML and that the cytogenetic responses suggest the possibility of greater efficacy in chronic-phase CML.