Allogeneic blood stem cell transplantation in chronic myeloid leukaemia-chronic phase following conditioning with busulphan and cyclophosphamide: a follow up report.

ABSTRACT

BACKGROUND: Allogeneic bone marrow transplantation (BMT) or peripheral blood stem cell transplantation remains the only modality of treatment that can eradicate a leukaemia clone in the majority of patients with chronic myeloid leukaemia (CML). However, the advent of the targeted molecule imatinib mesylate (formerly STI-571) against the bcr-abl chimeric protein in the disease has brought the issue of managing newly diagnosed CML patients, especially those with available donors, to the crossroads. Although the curative potential of this agent remains unknown, it can produce complete cytogenetic response in > 60% of newly diagnosed patients. METHODS: From May 1991 to October 2002, a total of 55 Ph+ CML-chronic phase patients received oral busulphan 16 mg/kg and cyclophosphamide 120 mg/kg i.v. as a conditioning regimen. All patients received human leucocyte antigen (HLA)-identical sibling donor haematopoletic stem cells--bone marrow in 41 patients (74.5%) and peripheral blood stem cells in 14 (25.4%). Post-transplant prophylaxis for graft-versus-host disease included a short course of methotrexate (on days +1, +3, +6 and +11) and cyclosporin till day +180 in 38 patients (69.1%), while a combination of cyclosporin and methylprednisolone was used in the remaining 17 (29%). RESULTS: At a median follow up of 48 months (10-144 months), 26 patients (47.3%) are alive. Early mortality (100-day) occurred in 17 patients (30.9%). Acute graft-versus-host disease developed in 37 patients (67.3%), and was grade IV in 6 of them. Chronic graft-versus-host disease developed in 17 patients (30.9%). Relapse occurred in only 2 patients (3.6%) till date. The leukaemia-free survival is 64.3% in the peripheral stem cell group, whereas it is 41.5% in the bone marrow recipient group. CONCLUSION: Allogeneic BMT appears to result in eradication of CML and ensure disease-free survival in about half the patients. However, efforts should be made to prevent graft-versus-host disease and minimize early mortality.