Filgrastim is a granulocyte colony-stimulating factor (G-CSF)
analog used to stimulate the proliferation and differentiation
of granulocytes. It is produced by recombinant DNA technology.
The gene for human granulocyte colony-stimulating factor is inserted
into the genetic material of Escherichia coli. The G-CSF then
produced by E. coli is only slightly different from G-CSF naturally
made in humans.
Filgrastim is used to treat neutropenia (a low number of neutrophils),
stimulating the bone marrow to increase production of neutrophils.
Causes of neutropenia include chemotherapy and bone marrow transplantation.
Filgrastim is also used to increase the number of hematopoietic
stem cells in the blood before collection by leukapheresis for
use in hematopoietic stem cell transplantation.