[Sustained remission with allogeneic peripheral blood stem cell transplantation and subsequent maintenance therapy with dasatinib in a patient with myeloblastic crisis of imatinib-resistant CML].

ABSTRACT

A 45-year-old man with chronic myelogenous leukemia (CML) in the chronic phase was treated with imatinib mesylate (IM). Although partial cytogenetic response (CyR) was obtained in 3 months, the patient exhibited back pain after treatment with IM for 5 months. He was diagnosed with myeloblastic crisis of CML with 30% blasts in the bone marrow. An extramedullary tumor with a diameter of 5-cm was found adjacent to the pancreatic head. Mutation analysis of the bcr/abl chimeric gene was negative. After the treatment with dasatinib (140 mg/day) for 40 days, complete CyR was obtained by bone marrow examination and the extramedullary tumor shrunk resulting in partial response on computed tomography. Allogeneic peripheral blood stem cell transplantation (allo-PBSCT) was performed from his HLA-DR one locus-mismatched sister. He has been in molecular remission for 24 months after allo-PBSCT and maintenance therapy with dasatinib has been administered. Dasatinib was tolerable without severe adverse events before and after allo-PBSCT in this case.