Salvage chemotherapy with donor lymphocyte infusion and STI 571 in a patient relapsing with B-lymphoblastic phase chronic myeloid leukemia after allogeneic bone marrow transplantation.

Relapse is the main cause of treatment failure following hematopoietic stem cell transplantation for blastic phase chronic myeloid leukemia. Treatment options including donor lymphocyte infusion, second transplantation, interferon- and re-induction chemotherapy are often unsuccessful. We report a patient with blastic phase chronic myeloid leukemia relapsing after allogeneic stem cell transplantation. The post-transplant leukemia was characterized with B-lymphoid markers and multiple genetic abnormalities including double Ph-chromosomes. The disease was treated with three courses of salvage chemotherapy combined with donor lymphocyte infusion and bcr-abl tyrosine kinase inhibitor. The leukemia proved to be non-responsive both to immune therapy and STI 571. The presented case demonstrates the need for combination approaches in post-transplant relapsed leukemia and discusses the possible contributing mechanisms of STI-571 resistance.