This trial, sponsored by Amgen, Inc., which produces the recombinant methionyl human stem
cell factor (r-metHuSCF), also involves two other institutions. The primary objective is
determination of the safety of administering multiple doses of r-metHuSCF in the setting of
acquired aplastic anemia and evaluation of the effect of r-metHuSCF on peripheral blood
counts. Potential effects of r-metHuSCF on frequency of need for red cell or platelet
transfusions and on bone marrow morphology/cellularity will also be evaluated.