Second chronic phase before transplantation is crucial for improving survival of blastic phase chronic myeloid leukaemia

Because successful outcome after transplantation seems to depend in acute myeloid leukaemia (AML) and in chronic phase chronic myeloid leukaemia (CML) on disease status at the time of transplantation, we investigated whether FLAN (fludarabine, cytosine arabinoside, mitoxantrone) induction before allogeneic stem cell transplantation (allo-SCT) may be useful in blastic phase (BP)-CML. Twenty patients with BP-CML were studied: 10 patients received FLAN induction chemotherapy before proceeding to early allo-SCT, whereas 10 patients were submitted to bone marrow transplantation (BMT) without remission induction. Eight out of 10 (80%) patients achieved second chronic phase after one course of therapy with FLAN and seven patients (six in second chronic phase and one with partial response) were then submitted to allo-SCT. Of the six patients transplanted in the second chronic phase, all achieved molecular remission, four are still in second chronic phase, with intervals ranging from 10 to 54 months, whereas one patient died from infection having relapsed 14 months after SCT and one died of transplant-related complications in the second chronic phase. Mean durations of second chronic phase and survival after allo-SCT were both significantly longer than in the group of 10 BP-CML patients submitted to allo-SCT without FLAN remission induction treatment [22.4 (range 1-61) vs. 3.5 months (range 1-10) with FLAN and 22.7 (range 2-61) vs. 6.4 (range 1-16) months without FLAN]. We conclude that FLAN induction therapy followed by early allo-SCT appears to be effective in the treatment of BP-CML and could provide a curative possibility for BP-CML patients.