Successful treatment of minimal residual disease-positive Philadelphia chromosome-positive acute lymphoblastic leukemia with imatinib followed by reduced-intensity unrelated cord blood transplantation after allogeneic peripheral blood stem cell transplantation.

We describe a 35-year-old woman with Philadelphia chromosome—positive acute lymphoblastic leukemia (Ph+ ALL) who received allogeneic sibling donor peripheral blood stem cell transplantation (PBSCT) and entered a second complete remission. Upon detection of BCR-ABL transcripts after PBSCT, the patient received imatinib, leading to molecular remission. Following the failure of donor leukocyte infusions, she underwent reduced-intensity unrelated cord blood transplantation (RI-UCBT), and has continued durable molecular remission for more than 30 months without substantial graft-versus-host disease. Because of a lack of adverse effects of imatinib on transplantation outcome, a treatment strategy consisting of molecular monitoring-guided initiation of imatinib followed by RI-UCBT may be promising in the management of Ph+ ALL after allogeneic SCT.