A Phase 1/11 Trial of Recombinant Granulocyte-Macrophage Colony-Stimulating Factor for Children With Aplastic Anemia

Nine pediatric patients (median age, 8 years; range, 0.7 to 19 years), eight with refractory aplastic anemia and one with newly diagnosed aplasia, were enrolled in a phase 1/11 trial of recombinant human granulocyte-macrophage colonystimulating factor (rhGM-CSF) administered via continuous intravenous infusion. Doses ranged from 8 to 32 pglkgld. Six of eight evaluable patients responded with a significant rise in neutrophil count (median fourfold increase; range, 2.5to 31-fold) during the 28-day induction period. Five patients completed 2 further months of therapy (maintenance) with persistent or improved neutrophil responses. Three patients had bone marrow aspirates suggestive of increased erythropoiesis, although only one patient had improvement in peripheral hematocrit and platelet count. In the five patients completing maintenance, three experienced a rapid return to baseline counts after rhGM-CSF