Preliminary Results of Treatment with Filgrastim for Relapse of Leukemia and Myelodysplasia after Allogeneic Bone Marrow Transplantation

Background. Patients whose leukemia relapses after allogeneic bone marrow transplantation have a poor prognosis; few respond to further chemotherapy, and almost none survive over the long term. We present preliminary observations on the use of filgrastim (granulocyte colony-stimulating factor) for relapse after transplantation. Methods. Seven female patients with leukemia (one with chronic myelogenous leukemia, five with acute myelogenous leukemia, and one with a myelodysplastic syndrome that transformed into acute myelogenous leukemia) whose disease relapsed within 360 days after allogeneic bone marrow transplantation received filgrastim (5 μg per kilogram of body weight per day by subcutaneous injection) to reinduce remission by stimulating residual donor marrow cells. Cytogenetic analysis of bone marrow, fluorescence in situ hybridization, and determination of restriction-fragment-length polymorphisms were used to assess response and chimerism. Results. Three of the seven patients had a complete hematologic and cytogenetic remission, with reestablishment of hematopoiesis of donor origin. Mild chronic graftversus-host disease developed in one patient, and acute graft-versus-host disease in none. One patient had a relapse 12 months after treatment, and two others remained in remission after 10 and 11 months. In two of the patients with a response, fluorescence in situ hybridization demonstrated stimulation of donor cells without differentiation of the leukemic clone. Conclusions. Filgrastim may be effective in selected cases of leukemic relapse after allogeneic bone marrow transplantation.