indication

Increases leukocyte production, for treatment in non-myeloid cancer, neutropenia and bone marrow transplant.

pharmacology

Used in the treatment of chemotherapy-induced neutropenia by enhancing the production of neutrophils. Filgrastim acts on hematopoietic cells by binding to specific cell surface receptors thereby stimulating proliferation, differentiation, commitment, and end cell functional activation.

mechanism of action

Filgrastim binds to the G-CSF receptor. As a G-CSF analog, it controls proliferation of committed progenitor cells and influences their maturation into mature neutrophils. Filgrastim also stimulates the release of neutrophils from bone marrow storage pools and reduces their maturation time. Filgrastim acts to increase the phagocytic activity of mature neutrophils. In patients receiving cytotoxic chemotherapy, Filgrastim can accelerate neutrophil recovery, leading to a reduction in duration of the neutropenic phase

route of elimination

Filgrastim is primarily eliminated by the kidney and neutrophils/neutrophil precursors; the latter presumably involves binding of the growth factor to the G-CSF receptor on the cell surface, internalization of the growth factor-receptor complexes via endocytosis, and subsequent degradation inside the cells.