Remission-induction of acute lymphoblastic transformation of chronic myeloid leukaemia, followed by long-term maintenance therapy.

Acute lymphoblastic transformation of chronic myeloid leukaemia (LT-CML) of 7 consecutive patients was treated according to a remission-induction and maintenance therapy used for de novo acute lymphoblastic leukaemia (ALL). All 7 patients achieved a second chronic phase with a median remission duration of 15 months. Two patients showed an isolated central nervous system (CNS) relapse. This did not occur in the 4 patients, who received prophylactic therapy with intrathecal methotrexate. The second transformation was nonlymphoblastic in nature in 4 out of the 5 patients. A treatment protocol similar to that of a bad risk ALL, including long-term maintenance therapy and CNS-prophylaxis is indicated in lymphoblastic transformation of CML.