Phase II Pilot Study of Granulocyte Colony-Stimulating Factor for Inherited Bone Marrow Failure Syndromes

OBJECTIVES: I. Assess the efficacy of recombinant human granulocyte colony-stimulating factor (G-CSF) in raising the absolute neutrophil count, platelet count, and hemoglobin level in patients with inherited bone marrow failure syndromes. II. Assess the efficacy of a reduced maintenance dose in patients who respond to daily G-CSF. III. Assess the toxic effects of G-CSF in these patients. IV. Measure bone marrow progenitor colonies before and after G-CSF. V. Measure CD34-positive cells in marrow and blood before and after G-CSF using flow cytometry and immunohistochemistry.

PROTOCOL OUTLINE: Patients receive granulocyte colony-stimulating factor (G-CSF) subcutaneously every day for 8 weeks; nonresponders receive an increased dose for an additional 8 weeks. Patients who respond at week 8 or 16 are then tapered to a lower maintenance dose of G-CSF administered every other day through week 40. The dose is adjusted to maintain an absolute neutrophil count above 1500. Patients are removed from study for failure to achieve a complete response by week 16, unacceptable nonhematologic toxicity, the identification of a clonal karyotype in marrow, or the onset of leukemia.