Imatinib mesylate in chronic myeloid leukemia: a prospective, single arm, non-randomized study.

Chronic myeloid leukemia (CML) is a hematopoietic stem cell disorder characterized by the balanced reciprocal translocation t (9:22). The resulting fusion gene, the BCR-ABL, is responsible for oncogenesis. Imatinib mesylate is a novel molecule, which inhibits the protein product of this fusion gene and hence has been used in the treatment of CML. The present study evaluates 174 patients with CML treated with imatinib mesylate. Of these 174 patients, 97 were in chronic phase, 47 in accelerated phase and 30 patients had blast crisis. Patients in chronic phase received imatinib mesylate in the dose of 400-mg daily, while those in accelerated phase and blast crisis received 600 to 800 mg daily. Of the 97 patients with chronic phase, 49 patients (50.5%) achieved a major (major + complete) cytogenetic response. Of the 47 patients in accelerated phase, 10 patients (21.3%) achieved a major cytogenetic response and in 30 patients with blast crisis, 7 (23.3%) achieved a major cytogenetic response. Dermatitis, mucositis, neutropenia and thrombocytopenia were some of the major toxicities. Of interest, 121 of the 174 patients (69.5%) developed generalized hypopigmentation. We conclude that imatinib mesylate is a safe and effective first-line therapy for chronic myeloid leukemia.

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

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.