Phase I/H Study of Recombinant Human Granulocyte-Macrophage Colony-Stimulating Factor in Aplastic Anemia and Myelodysplastic Syndrome

We performed a phase I/Il study of the administration of recombinant human granulocyte-macrophage colonystimulating factor (GM-CSF) to patients with aplastic anemia or myelodysplastic syndrome. Doses ranging from 15 to 480 .tg/m2 were administered as a one-hour or fourhour intravenous infusion daily for 7 days or as a 1 2-hour infusion for 1 4 days. Temporary improvements were seen in granulocyte counts, monocyte counts, and reticulocyte counts in six of eight patients with aplastic anemia and five of seven patients with myelodysplastic syndromes. The patients with myelodysplastic syndromes had larger increases in granulocyte. monocyte. and reticulocyte counts than did those with aplastic anemia, and they also had increases in the numbers of eosinophils (two of seven),