Use of hematopoietic growth factors for treatment of aplastic anemia

The recent discovery and manufacture of recombinant human hematopoietic growth factors offers a novel approach to treating patients with aplastic anemia. There are ongoing preclinical trials of a number of recombinant proteins that demonstrate remarkable hematopoietic activity in a variety of bone marrow failure states. Moreover, there are preliminary results of phase I/II trials of the administration of granulocyte-macrophage colony-stimulating factor (GM-CSF) in patients with aplastic anemia. It appears that this factor, the first to reach the stage of actual clinical trials, effectively increases proliferation of myeloid cellular elements of the peripheral blood and bone marrow, particularly in patients with milder forms of aplastic anemia. The side effects of GM-CSF at low to moderate doses of the growth factor (less than 16 micrograms/kg/day) appear tolerable. These results suggest that GM-CSF holds promise as a therapeutic option for patients with aplastic anemia. Long-term clinical trials will be needed to assess accurately the role that GM-CSF and other promising hematopoietic growth factors can play in the treatment of this disease, relative to other therapies such as antithymocyte globulin and bone marrow transplantation.