Rationals for the development of the human hematopoietic colony stimulating factors as therapeutical useful drugs.

Proliferation and differentiation of stem cells within the bone marrow into different cell types circulating in the peripheral blood is regulated by a series of hierarchically acting growth mediators--the colony-stimulating factors. In recent years, the genes of some of these physiological glycoproteins were cloned by means of molecular biology, and thus highly purified recombinant protein can now be produced in large scale. This has provided access to profound investigation of the role of these factors and the mechanisms for their action with regard to their potential therapeutical use. Part of their properties as revealed by the various in vitro test systems and by corresponding efficacy models using laboratory animals could also be found in recently performed phase I clinical studies, i.e. for granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF). Perspectives for a potential use of these regulators as single therapy and in possible additive or synergistic combinations are currently intensively studied.